Bump version to 0.0.178

.github/workflows/ci.yaml

@@ -20,6 +20,9 @@ jobs:
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
+          toolchain: nightly-2022-11-01
+          override: true
+          components: rustfmt
       - uses: actions/cache@v3
         env:
           cache-name: cache-cargo
@@ -33,6 +36,12 @@ jobs:
             ${{ runner.os }}-build-
             ${{ runner.os }}-
       - run: cargo build --all --release
+      - run: ./target/release/ruff_dev generate-rules-table
+      - run: ./target/release/ruff_dev generate-options
+      - run: git diff --quiet README.md || echo "::error file=README.md::This file is outdated. You may have to rerun 'cargo dev generate-options' and/or 'cargo dev generate-rules-table'."
+      - run: ./target/release/ruff_dev generate-check-code-prefix && cargo fmt -- src/checks_gen.rs
+      - run: git diff --quiet src/checks_gen.rs || echo "::error file=src/checks_gen.rs::This file is outdated. You may have to rerun 'cargo dev generate-check-code-prefix'."
+      - run: git diff --exit-code -- README.md src/checks_gen.rs
 
   cargo_fmt:
     name: "cargo fmt"

.github/workflows/ruff.yaml

@@ -1,9 +1,8 @@
 name: "[ruff] Release"
 
 on:
-  create:
-    tags:
-      - v*
+  release:
+    types: [published]
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}

.pre-commit-config.yaml

@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.0.169
+    rev: v0.0.178
     hooks:
       - id: ruff
 

BREAKING_CHANGES.md

@@ -0,0 +1,10 @@
+# Breaking Changes
+
+## 0.0.178
+
+### Configuration files are now resolved hierarchically ([#1190](https://github.com/charliermarsh/ruff/pull/1190))
+
+`pyproject.toml` files are now resolved hierarchically, such that for each Python file, we find
+the first `pyproject.toml` file in its path, and use that to determine its lint settings.
+
+See the [README](https://github.com/charliermarsh/ruff#pyprojecttoml-discovery) for more.

Cargo.lock

@@ -724,7 +724,7 @@ checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
 
 [[package]]
 name = "flake8-to-ruff"
-version = "0.0.169-dev.0"
+version = "0.0.178-dev.0"
 dependencies = [
  "anyhow",
  "clap 4.0.29",
@@ -796,6 +796,12 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "glob"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
+
 [[package]]
 name = "globset"
 version = "0.4.9"
@@ -1821,7 +1827,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.169"
+version = "0.0.178"
 dependencies = [
  "annotate-snippets 0.9.1",
  "anyhow",
@@ -1841,6 +1847,7 @@ dependencies = [
  "fern",
  "filetime",
  "getrandom 0.2.8",
+ "glob",
  "globset",
  "insta",
  "itertools",
@@ -1874,7 +1881,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_dev"
-version = "0.0.169"
+version = "0.0.178"
 dependencies = [
  "anyhow",
  "clap 4.0.29",
@@ -1892,7 +1899,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_macros"
-version = "0.0.169"
+version = "0.0.178"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -1935,7 +1942,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=2edd0d264c50c7807bcff03a52a6509e8b7f187f#2edd0d264c50c7807bcff03a52a6509e8b7f187f"
 dependencies = [
  "num-bigint",
  "rustpython-common",
@@ -1945,7 +1952,7 @@ dependencies = [
 [[package]]
 name = "rustpython-common"
 version = "0.0.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=2edd0d264c50c7807bcff03a52a6509e8b7f187f#2edd0d264c50c7807bcff03a52a6509e8b7f187f"
 dependencies = [
  "ascii",
  "cfg-if 1.0.0",
@@ -1968,7 +1975,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=2edd0d264c50c7807bcff03a52a6509e8b7f187f#2edd0d264c50c7807bcff03a52a6509e8b7f187f"
 dependencies = [
  "bincode",
  "bitflags",
@@ -1985,7 +1992,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=2edd0d264c50c7807bcff03a52a6509e8b7f187f#2edd0d264c50c7807bcff03a52a6509e8b7f187f"
 dependencies = [
  "ahash",
  "anyhow",

Cargo.toml

@@ -6,7 +6,7 @@ members = [
 
 [package]
 name = "ruff"
-version = "0.0.169"
+version = "0.0.178"
 edition = "2021"
 rust-version = "1.65.0"
 
@@ -28,6 +28,7 @@ common-path = { version = "1.0.0" }
 dirs = { version = "4.0.0" }
 fern = { version = "0.6.1" }
 filetime = { version = "0.2.17" }
+glob = { version = "0.3.0" }
 globset = { version = "0.4.9" }
 itertools = { version = "0.10.5" }
 libcst = { git = "https://github.com/charliermarsh/LibCST", rev = "f2f0b7a487a8725d161fe8b3ed73a6758b21e177" }
@@ -41,11 +42,11 @@ quick-junit = { version = "0.3.2" }
 rayon = { version = "1.5.3" }
 regex = { version = "1.6.0" }
 ropey = { version = "1.5.0", features = ["cr_lines", "simd"], default-features = false }
-ruff_macros = { version = "0.0.169", path = "ruff_macros" }
+ruff_macros = { version = "0.0.178", path = "ruff_macros" }
 rustc-hash = { version = "1.1.0" }
-rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
-rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "2edd0d264c50c7807bcff03a52a6509e8b7f187f" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "2edd0d264c50c7807bcff03a52a6509e8b7f187f" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "2edd0d264c50c7807bcff03a52a6509e8b7f187f" }
 serde = { version = "1.0.147", features = ["derive"] }
 serde_json = { version = "1.0.87" }
 strum = { version = "0.24.1", features = ["strum_macros"] }

LICENSE

@@ -438,6 +438,31 @@ are:
     SOFTWARE.
   """
 
+- flake8-simplify, licensed as follows:
+  """
+    MIT License
+
+    Copyright (c) 2020 Martin Thoma
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in all
+    copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+    SOFTWARE.
+  """
+
 - isort, licensed as follows:
   """
     The MIT License (MIT)

README.md

@@ -41,6 +41,7 @@ Ruff is extremely actively developed and used in major open-source projects like
 - [Pydantic](https://github.com/pydantic/pydantic)
 - [Saleor](https://github.com/saleor/saleor)
 - [Hatch](https://github.com/pypa/hatch)
+- [Jupyter Server](https://github.com/jupyter-server/jupyter_server)
 
 Read the [launch blog post](https://notes.crmarsh.com/python-tooling-could-be-much-much-faster).
 
@@ -89,6 +90,7 @@ of [Conda](https://docs.conda.io/en/latest/):
    1. [flake8-print (T20)](#flake8-print-t20)
    1. [flake8-quotes (Q)](#flake8-quotes-q)
    1. [flake8-return (RET)](#flake8-return-ret)
+   1. [flake8-simplify (SIM)](#flake8-simplify-sim)
    1. [flake8-tidy-imports (TID)](#flake8-tidy-imports-tid)
    1. [flake8-unused-arguments (ARG)](#flake8-unused-arguments-arg)
    1. [eradicate (ERA)](#eradicate-era)
@@ -120,12 +122,18 @@ For **macOS Homebrew** and **Linuxbrew** users, Ruff is also available as [`ruff
 brew install ruff
 ```
 
-For Conda users, Ruff is also available as [`ruff`](https://anaconda.org/conda-forge/ruff) on `conda-forge`:
+For **Conda** users, Ruff is also available as [`ruff`](https://anaconda.org/conda-forge/ruff) on `conda-forge`:
 
 ```shell
 conda install -c conda-forge ruff
 ```
 
+For **Arch Linux** users, Ruff is also available as [`ruff`](https://archlinux.org/packages/community/x86_64/ruff/) on the official repositories:
+
+```shell
+pacman -S ruff
+```
+
 ### Usage
 
 To run Ruff, try any of the following:
@@ -147,7 +155,7 @@ Ruff also works with [pre-commit](https://pre-commit.com):
 ```yaml
 repos:
   - repo: https://github.com/charliermarsh/ruff-pre-commit
-    rev: v0.0.169
+    rev: v0.0.178
     hooks:
       - id: ruff
 ```
@@ -323,6 +331,40 @@ Options:
           Print version information
 ```
 
+### `pyproject.toml` discovery
+
+Similar to [ESLint](https://eslint.org/docs/latest/user-guide/configuring/configuration-files#cascading-and-hierarchy),
+Ruff supports hierarchical configuration, such that the "closest" `pyproject.toml` file in the
+directory hierarchy is used for every individual file, with all paths in the `pyproject.toml` file
+(e.g., `exclude` globs, `src` paths) being resolved relative to the directory containing the
+`pyproject.toml` file.
+
+There are a few exceptions to these rules:
+
+1. If a configuration file is passed directly via `--config`, those settings are used for across
+   files. Any relative paths in that configuration file (like `exclude` globs or `src` paths) are
+   resolved relative to the _current working directory_.
+2. If no `pyproject.toml` file is found in the filesystem hierarchy, Ruff will fall back to using
+   a default configuration. If a user-specific configuration file exists at `${config_dir}/ruff/pyproject.toml`,
+   that file will be used instead of the default configuration, with `${config_dir}` being determined
+   via the [`dirs](https://docs.rs/dirs/4.0.0/dirs/fn.config_dir.html) crate, and all relative paths
+   being again resolved relative to the _current working directory_.
+3. Any `pyproject.toml`-supported settings that are provided on the command-line (e.g., via
+   `--select`) will override the settings in _every_ resolved configuration file.
+
+Unlike [ESLint](https://eslint.org/docs/latest/user-guide/configuring/configuration-files#cascading-and-hierarchy),
+Ruff does not merge settings across configuration files; instead, the "closest" configuration file
+is used, and any parent configuration files are ignored. In lieu of this implicit cascade, Ruff
+supports an [`extend`](#extend) field, which allows you to inherit the settings from another
+`pyproject.toml` file, like so:
+
+```toml
+# Extend the `pyproject.toml` file in the parent directory.
+extend = "../pyproject.toml"
+# But use a different line length.
+line-length = 100
+```
+
 ### Ignoring errors
 
 To omit a lint check entirely, add it to the "ignore" list via [`ignore`](#ignore) or
@@ -362,7 +404,7 @@ For targeted exclusions across entire files (e.g., "Ignore all F841 violations i
 ### "Action Comments"
 
 Ruff respects `isort`'s ["Action Comments"](https://pycqa.github.io/isort/docs/configuration/action_comments.html)
-(`# isort: skip_file`, `# isort: on`, `# isort: off`, `# isort: skip`, and `isort: split`), which
+(`# isort: skip_file`, `# isort: on`, `# isort: off`, `# isort: skip`, and `# isort: split`), which
 enable selectively enabling and disabling import sorting for blocks of code and other inline
 configuration.
 
@@ -412,14 +454,14 @@ For more, see [Pyflakes](https://pypi.org/project/pyflakes/2.5.0/) on PyPI.
 | F501 | PercentFormatInvalidFormat | '...' % ... has invalid format string: ... |  |
 | F502 | PercentFormatExpectedMapping | '...' % ... expected mapping but got sequence |  |
 | F503 | PercentFormatExpectedSequence | '...' % ... expected sequence but got mapping |  |
-| F504 | PercentFormatExtraNamedArguments | '...' % ... has unused named argument(s): ... |  |
+| F504 | PercentFormatExtraNamedArguments | '...' % ... has unused named argument(s): ... | 🛠 |
 | F505 | PercentFormatMissingArgument | '...' % ... is missing argument(s) for placeholder(s): ... |  |
 | F506 | PercentFormatMixedPositionalAndNamed | '...' % ... has mixed positional and named placeholders |  |
 | F507 | PercentFormatPositionalCountMismatch | '...' % ... has 4 placeholder(s) but 2 substitution(s) |  |
 | F508 | PercentFormatStarRequiresSequence | '...' % ... `*` specifier requires sequence |  |
 | F509 | PercentFormatUnsupportedFormatCharacter | '...' % ... has unsupported format character 'c' |  |
 | F521 | StringDotFormatInvalidFormat | '...'.format(...) has invalid format string: ... |  |
-| F522 | StringDotFormatExtraNamedArguments | '...'.format(...) has unused named argument(s): ... |  |
+| F522 | StringDotFormatExtraNamedArguments | '...'.format(...) has unused named argument(s): ... | 🛠 |
 | F523 | StringDotFormatExtraPositionalArguments | '...'.format(...) has unused arguments at position(s): ... |  |
 | F524 | StringDotFormatMissingArguments | '...'.format(...) is missing argument(s) for placeholder(s): ... |  |
 | F525 | StringDotFormatMixingAutomatic | '...'.format(...) mixes automatic and manual numbering |  |
@@ -438,11 +480,13 @@ For more, see [Pyflakes](https://pypi.org/project/pyflakes/2.5.0/) on PyPI.
 | F706 | ReturnOutsideFunction | `return` statement outside of a function/method |  |
 | F707 | DefaultExceptNotLast | An `except` block as not the last exception handler |  |
 | F722 | ForwardAnnotationSyntaxError | Syntax error in forward annotation: `...` |  |
+| F811 | RedefinedWhileUnused | Redefinition of unused `...` from line 1 |  |
 | F821 | UndefinedName | Undefined name `...` |  |
 | F822 | UndefinedExport | Undefined name `...` in `__all__` |  |
 | F823 | UndefinedLocal | Local variable `...` referenced before assignment |  |
 | F831 | DuplicateArgumentName | Duplicate argument name in function definition |  |
 | F841 | UnusedVariable | Local variable `...` is assigned to but never used |  |
+| F842 | UnusedAnnotation | Local variable `...` is annotated but never used |  |
 | F901 | RaiseNotImplemented | `raise NotImplemented` should be `raise NotImplementedError` | 🛠 |
 
 ### pycodestyle (E, W)
@@ -515,6 +559,7 @@ For more, see [pydocstyle](https://pypi.org/project/pydocstyle/6.1.1/) on PyPI.
 | D214 | SectionNotOverIndented | Section is over-indented ("Returns") | 🛠 |
 | D215 | SectionUnderlineNotOverIndented | Section underline is over-indented ("Returns") | 🛠 |
 | D300 | UsesTripleQuotes | Use """triple double quotes""" |  |
+| D301 | UsesRPrefixForBackslashedContent | Use r""" if any backslashes in a docstring |  |
 | D400 | EndsInPeriod | First line should end with a period | 🛠 |
 | D402 | NoSignature | First line should not be the function's signature |  |
 | D403 | FirstLineCapitalized | First word of the first line should be properly capitalized |  |
@@ -706,7 +751,7 @@ For more, see [flake8-comprehensions](https://pypi.org/project/flake8-comprehens
 | C409 | UnnecessaryLiteralWithinTupleCall | Unnecessary `(list\|tuple)` literal passed to `tuple()` (remove the outer call to `tuple()`) | 🛠 |
 | C410 | UnnecessaryLiteralWithinListCall | Unnecessary `(list\|tuple)` literal passed to `list()` (rewrite as a `list` literal) | 🛠 |
 | C411 | UnnecessaryListCall | Unnecessary `list` call (remove the outer call to `list()`) | 🛠 |
-| C413 | UnnecessaryCallAroundSorted | Unnecessary `(list\|reversed)` call around `sorted()` |  |
+| C413 | UnnecessaryCallAroundSorted | Unnecessary `(list\|reversed)` call around `sorted()` | 🛠 |
 | C414 | UnnecessaryDoubleCastOrProcess | Unnecessary `(list\|reversed\|set\|sorted\|tuple)` call within `(list\|set\|sorted\|tuple)()` |  |
 | C415 | UnnecessarySubscriptReversal | Unnecessary subscript reversal of iterable within `(reversed\|set\|sorted)()` |  |
 | C416 | UnnecessaryComprehension | Unnecessary `(list\|set)` comprehension (rewrite using `(list\|set)()`) | 🛠 |
@@ -761,6 +806,14 @@ For more, see [flake8-return](https://pypi.org/project/flake8-return/1.2.0/) on
 | RET507 | SuperfluousElseContinue | Unnecessary `else` after `continue` statement |  |
 | RET508 | SuperfluousElseBreak | Unnecessary `else` after `break` statement |  |
 
+### flake8-simplify (SIM)
+
+For more, see [flake8-simplify](https://pypi.org/project/flake8-simplify/0.19.3/) on PyPI.
+
+| Code | Name | Message | Fix |
+| ---- | ---- | ------- | --- |
+| SIM118 | KeyInDict | Use `key in dict` instead of `key in dict.keys()` | 🛠 |
+
 ### flake8-tidy-imports (TID)
 
 For more, see [flake8-tidy-imports](https://pypi.org/project/flake8-tidy-imports/4.8.0/) on PyPI.
@@ -806,12 +859,15 @@ For more, see [Pylint](https://pypi.org/project/pylint/2.15.7/) on PyPI.
 | PLC0414 | UselessImportAlias | Import alias does not rename original package | 🛠 |
 | PLC2201 | MisplacedComparisonConstant | Comparison should be ... | 🛠 |
 | PLC3002 | UnnecessaryDirectLambdaCall | Lambda expression called directly. Execute the expression inline instead. |  |
+| PLE0117 | NonlocalWithoutBinding | Nonlocal name `...` found without binding |  |
+| PLE0118 | UsedPriorGlobalDeclaration | Name `...` is used prior to global declaration on line 1 |  |
 | PLE1142 | AwaitOutsideAsync | `await` should be used within an async function |  |
 | PLR0206 | PropertyWithParameters | Cannot have defined parameters for properties |  |
-| PLR0402 | ConsiderUsingFromImport | Consider using `from ... import ...` |  |
-| PLR1701 | ConsiderMergingIsinstance | Consider merging these isinstance calls: `isinstance(..., (...))` |  |
-| PLR1722 | ConsiderUsingSysExit | Consider using `sys.exit()` | 🛠 |
+| PLR0402 | ConsiderUsingFromImport | Use `from ... import ...` in lieu of alias |  |
+| PLR1701 | ConsiderMergingIsinstance | Merge these isinstance calls: `isinstance(..., (...))` |  |
+| PLR1722 | UseSysExit | Use `sys.exit()` instead of `exit` | 🛠 |
 | PLW0120 | UselessElseOnLoop | Else clause on loop without a break statement, remove the else and de-indent all the code inside it |  |
+| PLW0602 | GlobalVariableNotAssigned | Using global for `...` but no assignment is done |  |
 
 ### Ruff-specific rules (RUF)
 
@@ -830,6 +886,37 @@ For more, see [Pylint](https://pypi.org/project/pylint/2.15.7/) on PyPI.
 
 Download the [Ruff VS Code extension](https://marketplace.visualstudio.com/items?itemName=charliermarsh.ruff).
 
+### Language Server Protocol
+
+Ruff is available as a [Language Server Protocol (LSP)](https://microsoft.github.io/language-server-protocol/)
+server, distributed as the [`python-lsp-ruff`](https://github.com/python-lsp/python-lsp-ruff) plugin
+for [`python-lsp-server`](https://github.com/python-lsp/python-lsp-server), both of which are
+installable via [PyPI](https://pypi.org/project/python-lsp-ruff/):
+
+```shell
+pip install python-lsp-server python-lsp-ruff
+```
+
+The LSP server can be used with any editor that supports the Language Server Protocol. For example,
+to use it with Neovim, you would add something like the following to your `init.lua`:
+
+```lua
+require'lspconfig'.pylsp.setup {
+  settings = {
+    pylsp = {
+      plugins = {
+        ruff = {
+          enabled = true
+        }
+      }
+    }
+  },
+}
+```
+
+[`ruffd`](https://github.com/Seamooo/ruffd) is another implementation of the Language Server
+Protocol (LSP) for Ruff, written in Rust.
+
 ### PyCharm
 
 Ruff can be installed as an [External Tool](https://www.jetbrains.com/help/pycharm/configuring-third-party-tools.html)
@@ -842,10 +929,13 @@ Ruff should then appear as a runnable action:
 
 ![Ruff as a runnable action](https://user-images.githubusercontent.com/1309177/193156026-732b0aaf-3dd9-4549-9b4d-2de6d2168a33.png)
 
-### Vim & Neovim (Unofficial)
+### Vim & Neovim
 
-Ruff is available as part of the [coc-pyright](https://github.com/fannheyward/coc-pyright) extension
-for coc.nvim.
+Ruff can be integrated into any editor that supports the Language Server Protocol (LSP) (see:
+[Language Server Protocol](#language-server-protocol)).
+
+Ruff is also available as part of the [coc-pyright](https://github.com/fannheyward/coc-pyright)
+extension for `coc.nvim`.
 
 <details>
 <summary>Ruff can also be integrated via <a href="https://github.com/neovim/nvim-lspconfig/blob/master/doc/server_configurations.md#efm"><code>efm</code></a> in just a <a href="https://github.com/JafarAbdi/myconfigs/blob/6f0b6b2450e92ec8fc50422928cd22005b919110/efm-langserver/config.yaml#L14-L20">few lines</a>.</summary>
@@ -901,11 +991,6 @@ null_ls.setup({
 
 </details>
 
-### Language Server Protocol (Unofficial)
-
-[`ruffd`](https://github.com/Seamooo/ruffd) is a Rust-based language server for Ruff that implements
-the Language Server Protocol (LSP).
-
 ### GitHub Actions
 
 GitHub Actions has everything you need to run Ruff out-of-the-box:
@@ -948,14 +1033,13 @@ automatically convert your existing configuration.)
 Ruff can be used as a drop-in replacement for Flake8 when used (1) without or with a small number of
 plugins, (2) alongside Black, and (3) on Python 3 code.
 
-Under those conditions, Ruff implements every rule in Flake8, with the exception of `F811`.
+Under those conditions, Ruff implements every rule in Flake8.
 
 Ruff also re-implements some of the most popular Flake8 plugins and related code quality tools
 natively, including:
 
-- [`isort`](https://pypi.org/project/isort/)
-- [`pydocstyle`](https://pypi.org/project/pydocstyle/)
-- [`pep8-naming`](https://pypi.org/project/pep8-naming/)
+- [`autoflake`](https://pypi.org/project/autoflake/) (1/7)
+- [`eradicate`](https://pypi.org/project/eradicate/)
 - [`flake8-2020`](https://pypi.org/project/flake8-2020/)
 - [`flake8-annotations`](https://pypi.org/project/flake8-annotations/)
 - [`flake8-bandit`](https://pypi.org/project/flake8-bandit/) (6/40)
@@ -973,12 +1057,13 @@ natively, including:
 - [`flake8-return`](https://pypi.org/project/flake8-return/)
 - [`flake8-super`](https://pypi.org/project/flake8-super/)
 - [`flake8-tidy-imports`](https://pypi.org/project/flake8-tidy-imports/) (1/3)
+- [`isort`](https://pypi.org/project/isort/)
 - [`mccabe`](https://pypi.org/project/mccabe/)
-- [`yesqa`](https://github.com/asottile/yesqa)
-- [`eradicate`](https://pypi.org/project/eradicate/)
-- [`pyupgrade`](https://pypi.org/project/pyupgrade/) (16/33)
+- [`pep8-naming`](https://pypi.org/project/pep8-naming/)
+- [`pydocstyle`](https://pypi.org/project/pydocstyle/)
 - [`pygrep-hooks`](https://github.com/pre-commit/pygrep-hooks) (1/10)
-- [`autoflake`](https://pypi.org/project/autoflake/) (1/7)
+- [`pyupgrade`](https://pypi.org/project/pyupgrade/) (16/33)
+- [`yesqa`](https://github.com/asottile/yesqa)
 
 Note that, in some cases, Ruff uses different error code prefixes than would be found in the
 originating Flake8 plugins. For example, Ruff uses `TID252` to represent the `I252` rule from
@@ -1009,8 +1094,6 @@ Pylint parity is being tracked in [#689](https://github.com/charliermarsh/ruff/i
 
 Today, Ruff can be used to replace Flake8 when used with any of the following plugins:
 
-- [`pydocstyle`](https://pypi.org/project/pydocstyle/)
-- [`pep8-naming`](https://pypi.org/project/pep8-naming/)
 - [`flake8-2020`](https://pypi.org/project/flake8-2020/)
 - [`flake8-annotations`](https://pypi.org/project/flake8-annotations/)
 - [`flake8-bandit`](https://pypi.org/project/flake8-bandit/) (6/40)
@@ -1029,6 +1112,8 @@ Today, Ruff can be used to replace Flake8 when used with any of the following pl
 - [`flake8-super`](https://pypi.org/project/flake8-super/)
 - [`flake8-tidy-imports`](https://pypi.org/project/flake8-tidy-imports/) (1/3)
 - [`mccabe`](https://pypi.org/project/mccabe/)
+- [`pep8-naming`](https://pypi.org/project/pep8-naming/)
+- [`pydocstyle`](https://pypi.org/project/pydocstyle/)
 
 Ruff can also replace [`isort`](https://pypi.org/project/isort/),
 [`yesqa`](https://github.com/asottile/yesqa), [`eradicate`](https://pypi.org/project/eradicate/),
@@ -1371,7 +1456,7 @@ Exclusions are based on globs, and can be either:
   (to exclude any Python files in `directory`). Note that these paths are relative to the
   project root (e.g., the directory containing your `pyproject.toml`).
 
-Note that you'll typically want to use [`extend_exclude`](#extend_exclude) to modify
+Note that you'll typically want to use [`extend-exclude`](#extend-exclude) to modify
 the excluded paths.
 
 **Default value**: `[".bzr", ".direnv", ".eggs", ".git", ".hg", ".mypy_cache", ".nox", ".pants.d", ".ruff_cache", ".svn", ".tox", ".venv", "__pypackages__", "_build", "buck-out", "build", "dist", "node_modules", "venv"]`
@@ -1387,6 +1472,30 @@ exclude = [".venv"]
 
 ---
 
+#### [`extend`](#extend)
+
+A path to a local `pyproject.toml` file to merge into this configuration.
+
+To resolve the current `pyproject.toml` file, Ruff will first resolve this base
+configuration file, then merge in any properties defined in the current configuration
+file.
+
+**Default value**: `None`
+
+**Type**: `Path`
+
+**Example usage**:
+
+```toml
+[tool.ruff]
+# Extend the `pyproject.toml` file in the parent directory.
+extend = "../pyproject.toml"
+# But use a different line length.
+line-length = 100
+```
+
+---
+
 #### [`extend-exclude`](#extend-exclude)
 
 A list of file patterns to omit from linting, in addition to those specified by `exclude`.
@@ -1644,6 +1753,25 @@ show-source = true
 
 The source code paths to consider, e.g., when resolving first- vs. third-party imports.
 
+As an example: given a Python package structure like:
+
+```text
+my_package/
+  pyproject.toml
+  src/
+    my_package/
+      __init__.py
+      foo.py
+      bar.py
+```
+
+The `src` directory should be included in `source` (e.g., `source = ["src"]`), such that
+when resolving imports, `my_package.foo` is considered a first-party import.
+
+This field supports globs. For example, if you have a series of Python packages in
+a `python_modules` directory, `src = ["python_modules/*"]` would expand to incorporate
+all of the packages in that directory.
+
 **Default value**: `["."]`
 
 **Type**: `Vec<PathBuf>`
@@ -1980,6 +2108,10 @@ from .utils import (
 )
 ```
 
+Note that this setting is only effective when combined with `combine-as-imports = true`.
+When `combine-as-imports` isn't enabled, every aliased `import from` will be given its
+own line, in which case, wrapping is not necessary.
+
 **Default value**: `false`
 
 **Type**: `bool`
@@ -1989,6 +2121,7 @@ from .utils import (
 ```toml
 [tool.ruff.isort]
 force-wrap-aliases = true
+combine-as-imports = true
 ```
 
 ---

flake8_to_ruff/Cargo.lock

@@ -771,7 +771,7 @@ checksum = "0ce7134b9999ecaf8bcd65542e436736ef32ddca1b3e06094cb6ec5755203b80"
 
 [[package]]
 name = "flake8_to_ruff"
-version = "0.0.169"
+version = "0.0.178"
 dependencies = [
  "anyhow",
  "clap",
@@ -1975,7 +1975,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.0.169"
+version = "0.0.178"
 dependencies = [
  "anyhow",
  "bincode",
@@ -2028,7 +2028,7 @@ dependencies = [
 [[package]]
 name = "rustpython-ast"
 version = "0.1.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=2edd0d264c50c7807bcff03a52a6509e8b7f187f#2edd0d264c50c7807bcff03a52a6509e8b7f187f"
 dependencies = [
  "num-bigint",
  "rustpython-common",
@@ -2038,7 +2038,7 @@ dependencies = [
 [[package]]
 name = "rustpython-common"
 version = "0.0.0"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=2edd0d264c50c7807bcff03a52a6509e8b7f187f#2edd0d264c50c7807bcff03a52a6509e8b7f187f"
 dependencies = [
  "ascii",
  "cfg-if 1.0.0",
@@ -2061,7 +2061,7 @@ dependencies = [
 [[package]]
 name = "rustpython-compiler-core"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=2edd0d264c50c7807bcff03a52a6509e8b7f187f#2edd0d264c50c7807bcff03a52a6509e8b7f187f"
 dependencies = [
  "bincode",
  "bitflags",
@@ -2078,7 +2078,7 @@ dependencies = [
 [[package]]
 name = "rustpython-parser"
 version = "0.1.2"
-source = "git+https://github.com/RustPython/RustPython.git?rev=28f9f65ccc625f00835d84bbb5fba274dce5aa89#28f9f65ccc625f00835d84bbb5fba274dce5aa89"
+source = "git+https://github.com/RustPython/RustPython.git?rev=2edd0d264c50c7807bcff03a52a6509e8b7f187f#2edd0d264c50c7807bcff03a52a6509e8b7f187f"
 dependencies = [
  "ahash",
  "anyhow",

flake8_to_ruff/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "flake8-to-ruff"
-version = "0.0.169-dev.0"
+version = "0.0.178-dev.0"
 edition = "2021"
 
 [lib]

flake8_to_ruff/src/converter.rs

@@ -246,6 +246,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -291,6 +292,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -336,6 +338,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -381,6 +384,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -426,6 +430,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -479,6 +484,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,
@@ -512,6 +518,7 @@ mod tests {
                 CheckCodePrefix::D214,
                 CheckCodePrefix::D215,
                 CheckCodePrefix::D300,
+                CheckCodePrefix::D301,
                 CheckCodePrefix::D400,
                 CheckCodePrefix::D403,
                 CheckCodePrefix::D404,
@@ -559,6 +566,7 @@ mod tests {
             allowed_confusables: None,
             dummy_variable_rgx: None,
             exclude: None,
+            extend: None,
             extend_exclude: None,
             extend_ignore: None,
             extend_select: None,

flake8_to_ruff/src/parser.rs

@@ -135,7 +135,6 @@ fn tokenize_files_to_codes_mapping(value: &str) -> Vec<Token> {
 }
 
 /// Parse a 'files-to-codes' mapping, mimicking Flake8's internal logic.
-///
 /// See: <https://github.com/PyCQA/flake8/blob/7dfe99616fc2f07c0017df2ba5fa884158f3ea8a/src/flake8/utils.py#L45>
 pub fn parse_files_to_codes_mapping(value: &str) -> Result<Vec<PatternPrefixPair>> {
     if value.trim().is_empty() {

flake8_to_ruff/src/plugin.rs

@@ -18,6 +18,7 @@ pub enum Plugin {
     Flake8Print,
     Flake8Quotes,
     Flake8Return,
+    Flake8Simplify,
     Flake8TidyImports,
     McCabe,
     PEP8Naming,
@@ -41,6 +42,7 @@ impl FromStr for Plugin {
             "flake8-print" => Ok(Plugin::Flake8Print),
             "flake8-quotes" => Ok(Plugin::Flake8Quotes),
             "flake8-return" => Ok(Plugin::Flake8Return),
+            "flake8-simplify" => Ok(Plugin::Flake8Simplify),
             "flake8-tidy-imports" => Ok(Plugin::Flake8TidyImports),
             "mccabe" => Ok(Plugin::McCabe),
             "pep8-naming" => Ok(Plugin::PEP8Naming),
@@ -65,6 +67,7 @@ impl Plugin {
             Plugin::Flake8Print => CheckCodePrefix::T2,
             Plugin::Flake8Quotes => CheckCodePrefix::Q,
             Plugin::Flake8Return => CheckCodePrefix::RET,
+            Plugin::Flake8Simplify => CheckCodePrefix::SIM,
             Plugin::Flake8TidyImports => CheckCodePrefix::I25,
             Plugin::McCabe => CheckCodePrefix::C9,
             Plugin::PEP8Naming => CheckCodePrefix::N,
@@ -101,6 +104,7 @@ impl Plugin {
             Plugin::Flake8Print => vec![CheckCodePrefix::T2],
             Plugin::Flake8Quotes => vec![CheckCodePrefix::Q],
             Plugin::Flake8Return => vec![CheckCodePrefix::RET],
+            Plugin::Flake8Simplify => vec![CheckCodePrefix::SIM],
             Plugin::Flake8TidyImports => vec![CheckCodePrefix::I25],
             Plugin::McCabe => vec![CheckCodePrefix::C9],
             Plugin::PEP8Naming => vec![CheckCodePrefix::N],
@@ -162,6 +166,7 @@ impl DocstringConvention {
                 // CheckCodePrefix::D214,
                 // CheckCodePrefix::D215,
                 CheckCodePrefix::D300,
+                CheckCodePrefix::D301,
                 CheckCodePrefix::D400,
                 CheckCodePrefix::D402,
                 CheckCodePrefix::D403,
@@ -209,6 +214,7 @@ impl DocstringConvention {
                 CheckCodePrefix::D214,
                 CheckCodePrefix::D215,
                 CheckCodePrefix::D300,
+                CheckCodePrefix::D301,
                 CheckCodePrefix::D400,
                 // CheckCodePrefix::D402,
                 CheckCodePrefix::D403,
@@ -257,6 +263,7 @@ impl DocstringConvention {
                 CheckCodePrefix::D214,
                 // CheckCodePrefix::D215,
                 CheckCodePrefix::D300,
+                CheckCodePrefix::D301,
                 // CheckCodePrefix::D400,
                 CheckCodePrefix::D402,
                 CheckCodePrefix::D403,
@@ -394,6 +401,7 @@ pub fn infer_plugins_from_codes(codes: &BTreeSet<CheckCodePrefix>) -> Vec<Plugin
         Plugin::Flake8Print,
         Plugin::Flake8Quotes,
         Plugin::Flake8Return,
+        Plugin::Flake8Simplify,
         Plugin::Flake8TidyImports,
         Plugin::PEP8Naming,
         Plugin::Pyupgrade,

resources/test/fixtures/README.md

@@ -0,0 +1,3 @@
+# fixtures
+
+Fixture files used for snapshot testing.

resources/test/fixtures/eradicate/ERA001.py

@@ -5,9 +5,11 @@ a = 4
 #foo(1, 2, 3)
 
 def foo(x, y, z):
-    contentet = 1 # print('hello')
+    content = 1 # print('hello')
     print(x, y, z)
 
     # This is a real comment.
     #return True
     return False
+
+#import os  # noqa: ERA001

resources/test/fixtures/flake8_return/RET504.py

@@ -130,6 +130,12 @@ def x():
     return val
 
 
+def x():
+    a = 1
+    print(f"a={a}")
+    return a
+
+
 # Test cases for using value for assignment then returning it
 # See:https://github.com/afonasev/flake8-return/issues/47
 def resolve_from_url(self, url: str) -> dict:

resources/test/fixtures/flake8_simplify/SIM118.py

@@ -0,0 +1,12 @@
+key in dict.keys() # SIM118
+
+foo["bar"] in dict.keys() # SIM118
+
+foo() in dict.keys() # SIM118
+
+for key in dict.keys(): # SIM118
+    pass
+
+for key in list(dict.keys()):
+    if some_property(key):
+        del dict[key]

resources/test/fixtures/isort/insert_empty_lines.py

@@ -39,3 +39,27 @@ if True:
     import collections
     import typing
     def f(): pass
+
+
+import os
+
+# Comment goes here.
+
+def f():
+    pass
+
+
+import os
+
+# Comment goes here.
+def f():
+    pass
+
+
+import os
+
+# Comment goes here.
+
+# And another.
+def f():
+    pass

resources/test/fixtures/isort/insert_empty_lines.pyi

@@ -0,0 +1,65 @@
+import a
+import b
+x = 1
+import os
+import sys
+def f():
+    pass
+if True:
+    x = 1
+    import collections
+    import typing
+class X: pass
+y = 1
+import os
+import sys
+"""Docstring"""
+
+if True:
+    import os
+
+
+def f():
+    pass
+
+
+if True:
+    import os
+def f():
+    pass
+
+if True:
+    x = 1
+    import collections
+    import typing
+    class X: pass
+
+if True:
+    x = 1
+    import collections
+    import typing
+    def f(): pass
+
+
+import os
+
+# Comment goes here.
+
+def f():
+    pass
+
+
+import os
+
+# Comment goes here.
+def f():
+    pass
+
+
+import os
+
+# Comment goes here.
+
+# And another.
+def f():
+    pass

resources/test/fixtures/pyflakes/F504.py

@@ -4,3 +4,6 @@ a = "wrong"
 
 hidden = {"a": "!"}
 "%(a)s %(c)s" % {"x": 1, **hidden}  # Ok (cannot see through splat)
+
+"%(a)s" % {"a": 1, r"b": "!"}  # F504 ("b" not used)
+"%(a)s" % {'a': 1, u"b": "!"}  # F504 ("b" not used)

resources/test/fixtures/pyflakes/F541.py

@@ -9,3 +9,4 @@ e = (
 )
 
 g = f"ghi{123:{45}}"
+h = "x" "y" f"z"

resources/test/fixtures/pyflakes/F811_0.py

@@ -0,0 +1,11 @@
+def foo(x):
+    return x
+
+
+@foo
+def bar():
+    pass
+
+
+def bar():
+    pass

resources/test/fixtures/pyflakes/F811_1.py

@@ -0,0 +1 @@
+import fu as FU, bar as FU

resources/test/fixtures/pyflakes/F811_10.py

@@ -0,0 +1,8 @@
+"""Test that importing a module twice using a nested does not issue a warning."""
+try:
+    if True:
+        if True:
+            import os
+except:
+    import os
+os.path

resources/test/fixtures/pyflakes/F811_11.py

@@ -0,0 +1,9 @@
+try:
+    from aa import mixer
+except AttributeError:
+    from bb import mixer
+except RuntimeError:
+    from cc import mixer
+except:
+    from dd import mixer
+mixer(123)

resources/test/fixtures/pyflakes/F811_12.py

@@ -0,0 +1,7 @@
+try:
+    from aa import mixer
+except ImportError:
+    pass
+else:
+    from bb import mixer
+mixer(123)

resources/test/fixtures/pyflakes/F811_13.py

@@ -0,0 +1,8 @@
+try:
+    import funca
+except ImportError:
+    from bb import funca
+    from bb import funcb
+else:
+    from bbb import funcb
+print(funca, funcb)

resources/test/fixtures/pyflakes/F811_14.py

@@ -0,0 +1,10 @@
+try:
+    import b
+except ImportError:
+    b = Ellipsis
+    from bb import a
+else:
+    from aa import a
+finally:
+    a = 42
+print(a, b)

resources/test/fixtures/pyflakes/F811_15.py

@@ -0,0 +1,5 @@
+import fu
+
+
+def fu():
+    pass

resources/test/fixtures/pyflakes/F811_16.py

@@ -0,0 +1,9 @@
+"""Test that shadowing a global with a nested function generates a warning."""
+
+import fu
+
+
+def bar():
+    def baz():
+        def fu():
+            pass

resources/test/fixtures/pyflakes/F811_17.py

@@ -0,0 +1,10 @@
+"""Test that shadowing a global name with a nested function generates a warning."""
+import fu
+
+
+def bar():
+    import fu
+
+    def baz():
+        def fu():
+            pass

resources/test/fixtures/pyflakes/F811_18.py

@@ -0,0 +1,14 @@
+"""Test that a global import which is redefined locally, but used later in another scope does not generate a warning."""
+
+import unittest, transport
+
+
+class GetTransportTestCase(unittest.TestCase):
+    def test_get_transport(self):
+        transport = 'transport'
+        self.assertIsNotNone(transport)
+
+
+class TestTransportMethodArgs(unittest.TestCase):
+    def test_send_defaults(self):
+        transport.Transport()

resources/test/fixtures/pyflakes/F811_19.py

@@ -0,0 +1,7 @@
+"""If an imported name is redefined by a class statement which also uses that name in the bases list, no warning is emitted."""
+
+from fu import bar
+
+
+class bar(bar):
+    pass

resources/test/fixtures/pyflakes/F811_2.py

@@ -0,0 +1 @@
+from moo import fu as FU, bar as FU

resources/test/fixtures/pyflakes/F811_20.py

@@ -0,0 +1,14 @@
+"""
+ Test that shadowing a global with a class attribute does not produce a
+ warning.
+ """
+
+import fu
+
+
+class bar:
+    # STOPSHIP: This errors.
+    fu = 1
+
+
+print(fu)

resources/test/fixtures/pyflakes/F811_3.py

@@ -0,0 +1 @@
+import fu; fu = 3

resources/test/fixtures/pyflakes/F811_4.py

@@ -0,0 +1 @@
+import fu; fu, bar = 3

resources/test/fixtures/pyflakes/F811_5.py

@@ -0,0 +1 @@
+import fu; [fu, bar] = 3

resources/test/fixtures/pyflakes/F811_6.py

@@ -0,0 +1,7 @@
+"""Test that importing a module twice within an if block does raise a warning."""
+
+i = 2
+if i == 1:
+    import os
+    import os
+os.path

resources/test/fixtures/pyflakes/F811_7.py

@@ -0,0 +1,8 @@
+"""Test that importing a module twice in if-else blocks does not raise a warning."""
+
+i = 2
+if i == 1:
+    import os
+else:
+    import os
+os.path

resources/test/fixtures/pyflakes/F811_8.py

@@ -0,0 +1,8 @@
+"""Test that importing a module twice in a try block does raise a warning."""
+
+try:
+    import os
+    import os
+except:
+    pass
+os.path

resources/test/fixtures/pyflakes/F811_9.py

@@ -0,0 +1,7 @@
+"""Test that importing a module twice in a try block does not raise a warning."""
+
+try:
+    import os
+except:
+    import os
+os.path

resources/test/fixtures/pyflakes/F821_6.py

@@ -0,0 +1,17 @@
+"""Test: annotated global."""
+
+
+n: int
+
+
+def f():
+    print(n)
+
+
+def g():
+    global n
+    n = 1
+
+
+g()
+f()

resources/test/fixtures/pyflakes/F842.py

@@ -0,0 +1,13 @@
+def f():
+    name: str
+    age: int
+
+
+class A:
+    name: str
+    age: int
+
+
+class B:
+    name: str = "Bob"
+    age: int = 18

resources/test/fixtures/pylint/global_variable_not_assigned.py

@@ -0,0 +1,32 @@
+###
+# Errors.
+###
+def f():
+    global x
+
+
+def f():
+    global x
+
+    print(x)
+
+
+###
+# Non-errors.
+###
+def f():
+    global x
+
+    x = 1
+
+
+def f():
+    global x
+
+    (x, y) = (1, 2)
+
+
+def f():
+    global x
+
+    del x

resources/test/fixtures/pylint/nonlocal_without_binding.py

@@ -0,0 +1,19 @@
+nonlocal x
+
+
+def f():
+    nonlocal x
+
+
+def f():
+    nonlocal y
+
+
+def f():
+    x = 1
+
+    def f():
+        nonlocal x
+
+    def f():
+        nonlocal y

resources/test/fixtures/pylint/used_prior_global_declaration.py

@@ -0,0 +1,148 @@
+###
+# Errors.
+###
+def f():
+    print(x)
+
+    global x
+
+    print(x)
+
+
+def f():
+    global x
+
+    print(x)
+
+    global x
+
+    print(x)
+
+
+def f():
+    print(x)
+
+    global x, y
+
+    print(x)
+
+
+def f():
+    global x, y
+
+    print(x)
+
+    global x, y
+
+    print(x)
+
+
+def f():
+    x = 1
+
+    global x
+
+    x = 1
+
+
+def f():
+    global x
+
+    x = 1
+
+    global x
+
+    x = 1
+
+
+def f():
+    del x
+
+    global x, y
+
+    del x
+
+
+def f():
+    global x, y
+
+    del x
+
+    global x, y
+
+    del x
+
+
+def f():
+    del x
+
+    global x
+
+    del x
+
+
+def f():
+    global x
+
+    del x
+
+    global x
+
+    del x
+
+
+def f():
+    del x
+
+    global x, y
+
+    del x
+
+
+def f():
+    global x, y
+
+    del x
+
+    global x, y
+
+    del x
+
+
+###
+# Non-errors.
+###
+def f():
+    global x
+
+    print(x)
+
+
+def f():
+    global x, y
+
+    print(x)
+
+
+def f():
+    global x
+
+    x = 1
+
+
+def f():
+    global x, y
+
+    x = 1
+
+
+def f():
+    global x
+
+    del x
+
+
+def f():
+    global x, y
+
+    del x

resources/test/fixtures/pylint/useless_else_on_loop.py

@@ -75,7 +75,7 @@ def test_break_in_orelse_deep():
 
 
 def test_break_in_orelse_deep2():
-    """should rise a useless-else-on-loop message, as the break statement is only
+    """should raise a useless-else-on-loop message, as the break statement is only
     for the inner for loop
     """
     for _ in range(10):
@@ -101,3 +101,15 @@ def test_break_in_orelse_deep3():
     else:
         return True
     return False
+
+
+def test_break_in_if_orelse():
+    """should raise a useless-else-on-loop message due to break in else"""
+    for _ in range(10):
+        if 1 < 2:  # pylint: disable=comparison-of-constants
+            pass
+        else:
+            break
+    else:
+        return True
+    return False

resources/test/project/README.md

@@ -0,0 +1,73 @@
+# project
+
+An example multi-package Python project used to test setting resolution and other complex
+behaviors.
+
+## Expected behavior
+
+Running from the repo root should pick up and enforce the appropriate settings for each package:
+
+```
+∴ cargo run resources/test/project/
+Found 5 error(s).
+resources/test/project/examples/docs/docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
+resources/test/project/examples/docs/docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/src/file.py:1:8: F401 `os` imported but unused
+resources/test/project/src/file.py:5:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/src/import_file.py:1:1: I001 Import block is un-sorted or un-formatted
+3 potentially fixable with the --fix option.
+```
+
+Running from the project directory itself should exhibit the same behavior:
+
+```
+∴ cd resources/test/project/ && cargo run .
+Found 5 error(s).
+examples/docs/docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
+examples/docs/docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
+src/file.py:1:8: F401 `os` imported but unused
+src/file.py:5:5: F841 Local variable `x` is assigned to but never used
+src/import_file.py:1:1: I001 Import block is un-sorted or un-formatted
+3 potentially fixable with the --fix option.
+```
+
+Running from the sub-package directory should exhibit the same behavior, but omit the top-level
+files:
+
+```
+∴ cd resources/test/project/examples/docs && cargo run .
+Found 2 error(s).
+docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
+docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
+1 potentially fixable with the --fix option.
+```
+
+`--config` should force Ruff to use the specified `pyproject.toml` for all files, and resolve
+file paths from the current working directory:
+
+```
+∴ cargo run -- --config=resources/test/project/pyproject.toml resources/test/project/
+Found 9 error(s).
+resources/test/project/examples/docs/docs/concepts/file.py:1:8: F401 `os` imported but unused
+resources/test/project/examples/docs/docs/concepts/file.py:5:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/examples/docs/docs/file.py:1:8: F401 `os` imported but unused
+resources/test/project/examples/docs/docs/file.py:3:8: F401 `numpy` imported but unused
+resources/test/project/examples/docs/docs/file.py:4:27: F401 `docs.concepts.file` imported but unused
+resources/test/project/examples/docs/docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/src/file.py:1:8: F401 `os` imported but unused
+resources/test/project/src/file.py:5:5: F841 Local variable `x` is assigned to but never used
+resources/test/project/src/import_file.py:1:1: I001 Import block is un-sorted or un-formatted
+6 potentially fixable with the --fix option.
+```
+
+Running from a parent directory should this "ignore" the `exclude` (hence, `concepts/file.py` gets
+included in the output):
+
+```
+∴ cd resources/test/project/examples && cargo run -- --config=docs/pyproject.toml .
+Found 3 error(s).
+docs/docs/concepts/file.py:5:5: F841 Local variable `x` is assigned to but never used
+docs/docs/file.py:1:1: I001 Import block is un-sorted or un-formatted
+docs/docs/file.py:8:5: F841 Local variable `x` is assigned to but never used
+1 potentially fixable with the --fix option.
+```

resources/test/project/examples/docs/docs/concepts/file.py

@@ -0,0 +1,5 @@
+import os
+
+
+def f():
+    x = 1

resources/test/project/examples/docs/docs/file.py

@@ -0,0 +1,8 @@
+import os
+
+import numpy as np
+from docs.concepts import file
+
+
+def f():
+    x = 1

resources/test/project/examples/docs/pyproject.toml

@@ -0,0 +1,6 @@
+[tool.ruff]
+extend = "../../pyproject.toml"
+src = ["."]
+extend-select = ["I001"]
+extend-ignore = ["F401"]
+extend-exclude = ["./docs/concepts/file.py"]

resources/test/project/pyproject.toml

@@ -0,0 +1,3 @@
+[tool.ruff]
+src = [".", "python_modules/*"]
+extend-select = ["I001"]

resources/test/project/src/file.py

@@ -0,0 +1,5 @@
+import os
+
+
+def f():
+    x = 1

resources/test/project/src/import_file.py

@@ -0,0 +1,7 @@
+import numpy as np
+from app import app_file
+from core import core_file
+
+np.array([1, 2, 3])
+app_file()
+core_file()

ruff_dev/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_dev"
-version = "0.0.169"
+version = "0.0.178"
 edition = "2021"
 
 [dependencies]
@@ -11,8 +11,8 @@ itertools = { version = "0.10.5" }
 libcst = { git = "https://github.com/charliermarsh/LibCST", rev = "f2f0b7a487a8725d161fe8b3ed73a6758b21e177" }
 once_cell = { version = "1.16.0" }
 ruff = { path = ".." }
-rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
-rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
-rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "28f9f65ccc625f00835d84bbb5fba274dce5aa89" }
+rustpython-ast = { features = ["unparse"], git = "https://github.com/RustPython/RustPython.git", rev = "2edd0d264c50c7807bcff03a52a6509e8b7f187f" }
+rustpython-common = { git = "https://github.com/RustPython/RustPython.git", rev = "2edd0d264c50c7807bcff03a52a6509e8b7f187f" }
+rustpython-parser = { features = ["lalrpop"], git = "https://github.com/RustPython/RustPython.git", rev = "2edd0d264c50c7807bcff03a52a6509e8b7f187f" }
 strum = { version = "0.24.1", features = ["strum_macros"] }
 strum_macros = { version = "0.24.3" }

ruff_macros/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ruff_macros"
-version = "0.0.169"
+version = "0.0.178"
 edition = "2021"
 
 [lib]

src/ast/branch_detection.rs

@@ -0,0 +1,105 @@
+use std::cmp::Ordering;
+
+use rustc_hash::FxHashMap;
+use rustpython_ast::ExcepthandlerKind::ExceptHandler;
+use rustpython_ast::Stmt;
+use rustpython_parser::ast::StmtKind;
+
+use crate::ast::types::RefEquality;
+
+/// Return the common ancestor of `left` and `right` below `stop`, or `None`.
+fn common_ancestor<'a>(
+    left: &'a RefEquality<'a, Stmt>,
+    right: &'a RefEquality<'a, Stmt>,
+    stop: Option<&'a RefEquality<'a, Stmt>>,
+    depths: &'a FxHashMap<RefEquality<'a, Stmt>, usize>,
+    child_to_parent: &'a FxHashMap<RefEquality<'a, Stmt>, RefEquality<'a, Stmt>>,
+) -> Option<&'a RefEquality<'a, Stmt>> {
+    if let Some(stop) = stop {
+        if left == stop || right == stop {
+            return None;
+        }
+    }
+    if left == right {
+        return Some(left);
+    }
+
+    let left_depth = depths.get(left)?;
+    let right_depth = depths.get(right)?;
+    match left_depth.cmp(right_depth) {
+        Ordering::Less => common_ancestor(
+            left,
+            child_to_parent.get(right)?,
+            stop,
+            depths,
+            child_to_parent,
+        ),
+        Ordering::Equal => common_ancestor(
+            child_to_parent.get(left)?,
+            child_to_parent.get(right)?,
+            stop,
+            depths,
+            child_to_parent,
+        ),
+        Ordering::Greater => common_ancestor(
+            child_to_parent.get(left)?,
+            right,
+            stop,
+            depths,
+            child_to_parent,
+        ),
+    }
+}
+
+/// Return the alternative branches for a given node.
+fn alternatives<'a>(node: &'a RefEquality<'a, Stmt>) -> Vec<Vec<RefEquality<'a, Stmt>>> {
+    match &node.0.node {
+        StmtKind::If { body, .. } => vec![body.iter().map(RefEquality).collect()],
+        StmtKind::Try {
+            body,
+            handlers,
+            orelse,
+            ..
+        } => vec![body.iter().chain(orelse.iter()).map(RefEquality).collect()]
+            .into_iter()
+            .chain(handlers.iter().map(|handler| {
+                let ExceptHandler { body, .. } = &handler.node;
+                body.iter().map(RefEquality).collect()
+            }))
+            .collect(),
+        _ => vec![],
+    }
+}
+
+/// Return `true` if `node` is a descendent of any of the nodes in `ancestors`.
+fn descendant_of<'a>(
+    node: &RefEquality<'a, Stmt>,
+    ancestors: &[RefEquality<'a, Stmt>],
+    stop: &RefEquality<'a, Stmt>,
+    depths: &FxHashMap<RefEquality<'a, Stmt>, usize>,
+    child_to_parent: &FxHashMap<RefEquality<'a, Stmt>, RefEquality<'a, Stmt>>,
+) -> bool {
+    ancestors.iter().any(|ancestor| {
+        common_ancestor(node, ancestor, Some(stop), depths, child_to_parent).is_some()
+    })
+}
+
+/// Return `true` if `left` and `right` are on different branches of an `if` or
+/// `try` statement.
+pub fn different_forks<'a>(
+    left: &RefEquality<'a, Stmt>,
+    right: &RefEquality<'a, Stmt>,
+    depths: &FxHashMap<RefEquality<'a, Stmt>, usize>,
+    child_to_parent: &FxHashMap<RefEquality<'a, Stmt>, RefEquality<'a, Stmt>>,
+) -> bool {
+    if let Some(ancestor) = common_ancestor(left, right, None, depths, child_to_parent) {
+        for items in alternatives(ancestor) {
+            let l = descendant_of(left, &items, ancestor, depths, child_to_parent);
+            let r = descendant_of(right, &items, ancestor, depths, child_to_parent);
+            if l ^ r {
+                return true;
+            }
+        }
+    }
+    false
+}

src/ast/mod.rs

@@ -1,3 +1,4 @@
+pub mod branch_detection;
 pub mod cast;
 pub mod function_type;
 pub mod helpers;

src/ast/operations.rs

@@ -1,12 +1,15 @@
+use rustc_hash::FxHashMap;
 use rustpython_ast::{Cmpop, Located};
 use rustpython_parser::ast::{Constant, Expr, ExprKind, Stmt, StmtKind};
 use rustpython_parser::lexer;
 use rustpython_parser::lexer::Tok;
 
-use crate::ast::types::{BindingKind, Scope};
+use crate::ast::types::{Binding, BindingKind, Scope};
+use crate::ast::visitor;
+use crate::ast::visitor::Visitor;
 
 /// Extract the names bound to a given __all__ assignment.
-pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
+pub fn extract_all_names(stmt: &Stmt, scope: &Scope, bindings: &[Binding]) -> Vec<String> {
     fn add_to_names(names: &mut Vec<String>, elts: &[Expr]) {
         for elt in elts {
             if let ExprKind::Constant {
@@ -23,8 +26,8 @@ pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
 
     // Grab the existing bound __all__ values.
     if let StmtKind::AugAssign { .. } = &stmt.node {
-        if let Some(binding) = scope.values.get("__all__") {
-            if let BindingKind::Export(existing) = &binding.kind {
+        if let Some(index) = scope.values.get("__all__") {
+            if let BindingKind::Export(existing) = &bindings[*index].kind {
                 names.extend_from_slice(existing);
             }
         }
@@ -69,6 +72,38 @@ pub fn extract_all_names(stmt: &Stmt, scope: &Scope) -> Vec<String> {
     names
 }
 
+#[derive(Default)]
+struct GlobalVisitor<'a> {
+    globals: FxHashMap<&'a str, &'a Stmt>,
+}
+
+impl<'a> Visitor<'a> for GlobalVisitor<'a> {
+    fn visit_stmt(&mut self, stmt: &'a Stmt) {
+        match &stmt.node {
+            StmtKind::Global { names } => {
+                for name in names {
+                    self.globals.insert(name, stmt);
+                }
+            }
+            StmtKind::FunctionDef { .. }
+            | StmtKind::AsyncFunctionDef { .. }
+            | StmtKind::ClassDef { .. } => {
+                // Don't recurse.
+            }
+            _ => visitor::walk_stmt(self, stmt),
+        }
+    }
+}
+
+/// Extract a map from global name to its last-defining `Stmt`.
+pub fn extract_globals(body: &[Stmt]) -> FxHashMap<&str, &Stmt> {
+    let mut visitor = GlobalVisitor::default();
+    for stmt in body {
+        visitor.visit_stmt(stmt);
+    }
+    visitor.globals
+}
+
 /// Check if a node is parent of a conditional branch.
 pub fn on_conditional_branch<'a>(parents: &mut impl Iterator<Item = &'a Stmt>) -> bool {
     parents.any(|parent| {

src/ast/types.rs

@@ -32,23 +32,29 @@ impl Range {
 
 #[derive(Debug)]
 pub struct FunctionDef<'a> {
+    // Properties derived from StmtKind::FunctionDef.
     pub name: &'a str,
     pub args: &'a Arguments,
     pub body: &'a [Stmt],
     pub decorator_list: &'a [Expr],
     // pub returns: Option<&'a Expr>,
     // pub type_comment: Option<&'a str>,
+    // Scope-specific properties.
     // TODO(charlie): Create AsyncFunctionDef to mirror the AST.
     pub async_: bool,
+    pub globals: FxHashMap<&'a str, &'a Stmt>,
 }
 
 #[derive(Debug)]
 pub struct ClassDef<'a> {
+    // Properties derived from StmtKind::ClassDef.
     pub name: &'a str,
     pub bases: &'a [Expr],
     pub keywords: &'a [Keyword],
     // pub body: &'a [Stmt],
     pub decorator_list: &'a [Expr],
+    // Scope-specific properties.
+    pub globals: FxHashMap<&'a str, &'a Stmt>,
 }
 
 #[derive(Debug)]
@@ -73,7 +79,11 @@ pub struct Scope<'a> {
     pub kind: ScopeKind<'a>,
     pub import_starred: bool,
     pub uses_locals: bool,
-    pub values: FxHashMap<&'a str, Binding>,
+    /// A map from bound name to binding index.
+    pub values: FxHashMap<&'a str, usize>,
+    /// A list of (name, index) pairs for bindings that were overridden in the
+    /// scope.
+    pub overridden: Vec<(&'a str, usize)>,
 }
 
 impl<'a> Scope<'a> {
@@ -84,42 +94,120 @@ impl<'a> Scope<'a> {
             import_starred: false,
             uses_locals: false,
             values: FxHashMap::default(),
+            overridden: Vec::new(),
         }
     }
 }
 
-#[derive(Clone, Debug)]
-pub struct BindingContext {
-    pub defined_by: usize,
-    pub defined_in: Option<usize>,
-}
-
 #[derive(Clone, Debug)]
 pub enum BindingKind {
     Annotation,
     Argument,
     Assignment,
-    // TODO(charlie): This seems to be a catch-all.
     Binding,
     LoopVar,
     Global,
     Nonlocal,
     Builtin,
     ClassDefinition,
-    Definition,
+    FunctionDefinition,
     Export(Vec<String>),
     FutureImportation,
     StarImportation(Option<usize>, Option<String>),
-    Importation(String, String, BindingContext),
-    FromImportation(String, String, BindingContext),
-    SubmoduleImportation(String, String, BindingContext),
+    Importation(String, String),
+    FromImportation(String, String),
+    SubmoduleImportation(String, String),
 }
 
 #[derive(Clone, Debug)]
-pub struct Binding {
+pub struct Binding<'a> {
     pub kind: BindingKind,
     pub range: Range,
+    /// The statement in which the `Binding` was defined.
+    pub source: Option<RefEquality<'a, Stmt>>,
     /// Tuple of (scope index, range) indicating the scope and range at which
     /// the binding was last used.
     pub used: Option<(usize, Range)>,
 }
+
+// Pyflakes defines the following binding hierarchy (via inheritance):
+//   Binding
+//    ExportBinding
+//    Annotation
+//    Argument
+//    Assignment
+//      NamedExprAssignment
+//    Definition
+//      FunctionDefinition
+//      ClassDefinition
+//      Builtin
+//      Importation
+//        SubmoduleImportation
+//        ImportationFrom
+//        StarImportation
+//        FutureImportation
+
+impl<'a> Binding<'a> {
+    pub fn is_definition(&self) -> bool {
+        matches!(
+            self.kind,
+            BindingKind::ClassDefinition
+                | BindingKind::FunctionDefinition
+                | BindingKind::Builtin
+                | BindingKind::FutureImportation
+                | BindingKind::StarImportation(..)
+                | BindingKind::Importation(..)
+                | BindingKind::FromImportation(..)
+                | BindingKind::SubmoduleImportation(..)
+        )
+    }
+
+    pub fn redefines(&self, existing: &'a Binding) -> bool {
+        match &self.kind {
+            BindingKind::Importation(_, full_name) | BindingKind::FromImportation(_, full_name) => {
+                if let BindingKind::SubmoduleImportation(_, existing_full_name) = &existing.kind {
+                    return full_name == existing_full_name;
+                }
+            }
+            BindingKind::SubmoduleImportation(_, full_name) => {
+                if let BindingKind::Importation(_, existing_full_name)
+                | BindingKind::FromImportation(_, existing_full_name)
+                | BindingKind::SubmoduleImportation(_, existing_full_name) = &existing.kind
+                {
+                    return full_name == existing_full_name;
+                }
+            }
+            BindingKind::Annotation => {
+                return false;
+            }
+            BindingKind::FutureImportation => {
+                return false;
+            }
+            BindingKind::StarImportation(..) => {
+                return false;
+            }
+            _ => {}
+        }
+        existing.is_definition()
+    }
+}
+
+#[derive(Debug, Copy, Clone)]
+pub struct RefEquality<'a, T>(pub &'a T);
+
+impl<'a, T> std::hash::Hash for RefEquality<'a, T> {
+    fn hash<H>(&self, state: &mut H)
+    where
+        H: std::hash::Hasher,
+    {
+        (self.0 as *const T).hash(state);
+    }
+}
+
+impl<'a, 'b, T> PartialEq<RefEquality<'b, T>> for RefEquality<'a, T> {
+    fn eq(&self, other: &RefEquality<'b, T>) -> bool {
+        std::ptr::eq(self.0, other.0)
+    }
+}
+
+impl<'a, T> Eq for RefEquality<'a, T> {}

src/ast/visitor.rs

@@ -159,8 +159,8 @@ pub fn walk_stmt<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, stmt: &'a Stmt) {
             orelse,
             ..
         } => {
-            visitor.visit_expr(target);
             visitor.visit_expr(iter);
+            visitor.visit_expr(target);
             for stmt in body {
                 visitor.visit_stmt(stmt);
             }
@@ -175,8 +175,8 @@ pub fn walk_stmt<'a, V: Visitor<'a> + ?Sized>(visitor: &mut V, stmt: &'a Stmt) {
             orelse,
             ..
         } => {
-            visitor.visit_expr(target);
             visitor.visit_expr(iter);
+            visitor.visit_expr(target);
             for stmt in body {
                 visitor.visit_stmt(stmt);
             }

src/ast/whitespace.rs

@@ -1,3 +1,4 @@
+use std::borrow::Cow;
 use std::str::Lines;
 
 use rustpython_ast::{Located, Location};
@@ -5,31 +6,26 @@ use rustpython_ast::{Located, Location};
 use crate::ast::types::Range;
 use crate::check_ast::Checker;
 
+/// Extract the leading indentation from a line.
+pub fn indentation<'a, T>(checker: &'a Checker, located: &'a Located<T>) -> Cow<'a, str> {
+    let range = Range::from_located(located);
+    checker.locator.slice_source_code_range(&Range {
+        location: Location::new(range.location.row(), 0),
+        end_location: Location::new(range.location.row(), range.location.column()),
+    })
+}
+
 /// Extract the leading words from a line of text.
-pub fn leading_words(line: &str) -> String {
-    line.trim()
-        .chars()
-        .take_while(|char| char.is_alphanumeric() || char.is_whitespace())
-        .collect()
+pub fn leading_words(line: &str) -> &str {
+    let line = line.trim();
+    line.find(|char: char| !char.is_alphanumeric() && !char.is_whitespace())
+        .map_or(line, |index| &line[..index])
 }
 
 /// Extract the leading whitespace from a line of text.
-pub fn leading_space(line: &str) -> String {
-    line.chars()
-        .take_while(|char| char.is_whitespace())
-        .collect()
-}
-
-/// Extract the leading indentation from a line.
-pub fn indentation<T>(checker: &Checker, located: &Located<T>) -> String {
-    let range = Range::from_located(located);
-    checker
-        .locator
-        .slice_source_code_range(&Range {
-            location: Location::new(range.location.row(), 0),
-            end_location: Location::new(range.location.row(), range.location.column()),
-        })
-        .to_string()
+pub fn leading_space(line: &str) -> &str {
+    line.find(|char: char| !char.is_whitespace())
+        .map_or(line, |index| &line[..index])
 }
 
 /// Replace any non-whitespace characters from an indentation string.

src/autofix/fixer.rs

@@ -10,7 +10,7 @@ use crate::autofix::Fix;
 use crate::checks::Check;
 use crate::source_code_locator::SourceCodeLocator;
 
-#[derive(Hash)]
+#[derive(Debug, Hash)]
 pub enum Mode {
     Generate,
     Apply,

src/check_imports.rs

@@ -1,5 +1,7 @@
 //! Lint rules based on import analysis.
 
+use std::path::Path;
+
 use rustpython_parser::ast::Suite;
 
 use crate::ast::visitor::Visitor;
@@ -33,8 +35,9 @@ pub fn check_imports(
     directives: &IsortDirectives,
     settings: &Settings,
     autofix: bool,
+    path: &Path,
 ) -> Vec<Check> {
-    let mut tracker = ImportTracker::new(directives);
+    let mut tracker = ImportTracker::new(locator, directives, path);
     for stmt in python_ast {
         tracker.visit_stmt(stmt);
     }

src/checks.rs

@@ -87,22 +87,27 @@ pub enum CheckCode {
     F706,
     F707,
     F722,
+    F811,
     F821,
     F822,
     F823,
     F831,
     F841,
+    F842,
     F901,
     // pylint
     PLC0414,
     PLC2201,
     PLC3002,
+    PLE0117,
+    PLE0118,
     PLE1142,
     PLR0206,
     PLR0402,
     PLR1701,
     PLR1722,
     PLW0120,
+    PLW0602,
     // flake8-builtins
     A001,
     A002,
@@ -201,6 +206,8 @@ pub enum CheckCode {
     YTT301,
     YTT302,
     YTT303,
+    // flake8-simplify
+    SIM118,
     // pyupgrade
     UP001,
     UP003,
@@ -242,6 +249,7 @@ pub enum CheckCode {
     D214,
     D215,
     D300,
+    D301,
     D400,
     D402,
     D403,
@@ -331,6 +339,7 @@ pub enum CheckCategory {
     Flake8Print,
     Flake8Quotes,
     Flake8Return,
+    Flake8Simplify,
     Flake8TidyImports,
     Flake8UnusedArguments,
     Eradicate,
@@ -371,6 +380,7 @@ impl CheckCategory {
             CheckCategory::Flake8Quotes => "flake8-quotes",
             CheckCategory::Flake8Return => "flake8-return",
             CheckCategory::Flake8TidyImports => "flake8-tidy-imports",
+            CheckCategory::Flake8Simplify => "flake8-simplify",
             CheckCategory::Flake8UnusedArguments => "flake8-unused-arguments",
             CheckCategory::Isort => "isort",
             CheckCategory::McCabe => "mccabe",
@@ -400,6 +410,7 @@ impl CheckCategory {
             CheckCategory::Flake8Print => vec![CheckCodePrefix::T20],
             CheckCategory::Flake8Quotes => vec![CheckCodePrefix::Q],
             CheckCategory::Flake8Return => vec![CheckCodePrefix::RET],
+            CheckCategory::Flake8Simplify => vec![CheckCodePrefix::SIM],
             CheckCategory::Flake8TidyImports => vec![CheckCodePrefix::TID],
             CheckCategory::Flake8UnusedArguments => vec![CheckCodePrefix::ARG],
             CheckCategory::Isort => vec![CheckCodePrefix::I],
@@ -475,6 +486,10 @@ impl CheckCategory {
                 "https://pypi.org/project/flake8-return/1.2.0/",
                 &Platform::PyPI,
             )),
+            CheckCategory::Flake8Simplify => Some((
+                "https://pypi.org/project/flake8-simplify/0.19.3/",
+                &Platform::PyPI,
+            )),
             CheckCategory::Flake8TidyImports => Some((
                 "https://pypi.org/project/flake8-tidy-imports/4.8.0/",
                 &Platform::PyPI,
@@ -616,6 +631,7 @@ pub enum CheckKind {
     PercentFormatStarRequiresSequence,
     PercentFormatUnsupportedFormatCharacter(char),
     RaiseNotImplemented,
+    RedefinedWhileUnused(String, usize),
     ReturnOutsideFunction,
     StringDotFormatExtraNamedArguments(Vec<String>),
     StringDotFormatExtraPositionalArguments(Vec<String>),
@@ -625,20 +641,24 @@ pub enum CheckKind {
     TwoStarredExpressions,
     UndefinedExport(String),
     UndefinedLocal(String),
+    UnusedAnnotation(String),
     UndefinedName(String),
     UnusedImport(String, bool),
     UnusedVariable(String),
     YieldOutsideFunction(DeferralKeyword),
     // pylint
-    ConsiderMergingIsinstance(String, Vec<String>),
-    UselessImportAlias,
-    MisplacedComparisonConstant(String),
-    UnnecessaryDirectLambdaCall,
-    PropertyWithParameters,
-    ConsiderUsingFromImport(String, String),
     AwaitOutsideAsync,
+    ConsiderMergingIsinstance(String, Vec<String>),
+    ConsiderUsingFromImport(String, String),
+    GlobalVariableNotAssigned(String),
+    MisplacedComparisonConstant(String),
+    NonlocalWithoutBinding(String),
+    PropertyWithParameters,
+    UnnecessaryDirectLambdaCall,
+    UseSysExit(String),
+    UsedPriorGlobalDeclaration(String, usize),
     UselessElseOnLoop,
-    ConsiderUsingSysExit,
+    UselessImportAlias,
     // flake8-builtins
     BuiltinVariableShadowing(String),
     BuiltinArgumentShadowing(String),
@@ -735,6 +755,8 @@ pub enum CheckKind {
     SysVersion0Referenced,
     SysVersionCmpStr10,
     SysVersionSlice1Referenced,
+    // flake8-simplify
+    KeyInDict(String, String),
     // pyupgrade
     TypeOfPrimitive(Primitive),
     UselessMetaclassType,
@@ -794,6 +816,7 @@ pub enum CheckKind {
     SectionUnderlineMatchesSectionLength(String),
     SectionUnderlineNotOverIndented(String),
     SkipDocstring,
+    UsesRPrefixForBackslashedContent,
     UsesTripleQuotes,
     // pep8-naming
     InvalidClassName(String),
@@ -932,16 +955,20 @@ impl CheckCode {
             CheckCode::F706 => CheckKind::ReturnOutsideFunction,
             CheckCode::F707 => CheckKind::DefaultExceptNotLast,
             CheckCode::F722 => CheckKind::ForwardAnnotationSyntaxError("...".to_string()),
+            CheckCode::F811 => CheckKind::RedefinedWhileUnused("...".to_string(), 1),
             CheckCode::F821 => CheckKind::UndefinedName("...".to_string()),
             CheckCode::F822 => CheckKind::UndefinedExport("...".to_string()),
             CheckCode::F823 => CheckKind::UndefinedLocal("...".to_string()),
             CheckCode::F831 => CheckKind::DuplicateArgumentName,
             CheckCode::F841 => CheckKind::UnusedVariable("...".to_string()),
+            CheckCode::F842 => CheckKind::UnusedAnnotation("...".to_string()),
             CheckCode::F901 => CheckKind::RaiseNotImplemented,
             // pylint
             CheckCode::PLC0414 => CheckKind::UselessImportAlias,
             CheckCode::PLC2201 => CheckKind::MisplacedComparisonConstant("...".to_string()),
             CheckCode::PLC3002 => CheckKind::UnnecessaryDirectLambdaCall,
+            CheckCode::PLE0117 => CheckKind::NonlocalWithoutBinding("...".to_string()),
+            CheckCode::PLE0118 => CheckKind::UsedPriorGlobalDeclaration("...".to_string(), 1),
             CheckCode::PLE1142 => CheckKind::AwaitOutsideAsync,
             CheckCode::PLR0402 => {
                 CheckKind::ConsiderUsingFromImport("...".to_string(), "...".to_string())
@@ -950,8 +977,9 @@ impl CheckCode {
             CheckCode::PLR1701 => {
                 CheckKind::ConsiderMergingIsinstance("...".to_string(), vec!["...".to_string()])
             }
-            CheckCode::PLR1722 => CheckKind::ConsiderUsingSysExit,
+            CheckCode::PLR1722 => CheckKind::UseSysExit("exit".to_string()),
             CheckCode::PLW0120 => CheckKind::UselessElseOnLoop,
+            CheckCode::PLW0602 => CheckKind::GlobalVariableNotAssigned("...".to_string()),
             // flake8-builtins
             CheckCode::A001 => CheckKind::BuiltinVariableShadowing("...".to_string()),
             CheckCode::A002 => CheckKind::BuiltinArgumentShadowing("...".to_string()),
@@ -1065,6 +1093,8 @@ impl CheckCode {
             CheckCode::YTT303 => CheckKind::SysVersionSlice1Referenced,
             // flake8-blind-except
             CheckCode::BLE001 => CheckKind::BlindExcept("Exception".to_string()),
+            // flake8-simplify
+            CheckCode::SIM118 => CheckKind::KeyInDict("key".to_string(), "dict".to_string()),
             // pyupgrade
             CheckCode::UP001 => CheckKind::UselessMetaclassType,
             CheckCode::UP003 => CheckKind::TypeOfPrimitive(Primitive::Str),
@@ -1109,6 +1139,7 @@ impl CheckCode {
             CheckCode::D214 => CheckKind::SectionNotOverIndented("Returns".to_string()),
             CheckCode::D215 => CheckKind::SectionUnderlineNotOverIndented("Returns".to_string()),
             CheckCode::D300 => CheckKind::UsesTripleQuotes,
+            CheckCode::D301 => CheckKind::UsesRPrefixForBackslashedContent,
             CheckCode::D400 => CheckKind::EndsInPeriod,
             CheckCode::D402 => CheckKind::NoSignature,
             CheckCode::D403 => CheckKind::FirstLineCapitalized,
@@ -1289,6 +1320,7 @@ impl CheckCode {
             CheckCode::D214 => CheckCategory::Pydocstyle,
             CheckCode::D215 => CheckCategory::Pydocstyle,
             CheckCode::D300 => CheckCategory::Pydocstyle,
+            CheckCode::D301 => CheckCategory::Pydocstyle,
             CheckCode::D400 => CheckCategory::Pydocstyle,
             CheckCode::D402 => CheckCategory::Pydocstyle,
             CheckCode::D403 => CheckCategory::Pydocstyle,
@@ -1359,11 +1391,13 @@ impl CheckCode {
             CheckCode::F706 => CheckCategory::Pyflakes,
             CheckCode::F707 => CheckCategory::Pyflakes,
             CheckCode::F722 => CheckCategory::Pyflakes,
+            CheckCode::F811 => CheckCategory::Pyflakes,
             CheckCode::F821 => CheckCategory::Pyflakes,
             CheckCode::F822 => CheckCategory::Pyflakes,
             CheckCode::F823 => CheckCategory::Pyflakes,
             CheckCode::F831 => CheckCategory::Pyflakes,
             CheckCode::F841 => CheckCategory::Pyflakes,
+            CheckCode::F842 => CheckCategory::Pyflakes,
             CheckCode::F901 => CheckCategory::Pyflakes,
             CheckCode::FBT001 => CheckCategory::Flake8BooleanTrap,
             CheckCode::FBT002 => CheckCategory::Flake8BooleanTrap,
@@ -1390,12 +1424,15 @@ impl CheckCode {
             CheckCode::PLC0414 => CheckCategory::Pylint,
             CheckCode::PLC2201 => CheckCategory::Pylint,
             CheckCode::PLC3002 => CheckCategory::Pylint,
+            CheckCode::PLE0117 => CheckCategory::Pylint,
+            CheckCode::PLE0118 => CheckCategory::Pylint,
             CheckCode::PLE1142 => CheckCategory::Pylint,
             CheckCode::PLR0206 => CheckCategory::Pylint,
             CheckCode::PLR0402 => CheckCategory::Pylint,
             CheckCode::PLR1701 => CheckCategory::Pylint,
             CheckCode::PLR1722 => CheckCategory::Pylint,
             CheckCode::PLW0120 => CheckCategory::Pylint,
+            CheckCode::PLW0602 => CheckCategory::Pylint,
             CheckCode::Q000 => CheckCategory::Flake8Quotes,
             CheckCode::Q001 => CheckCategory::Flake8Quotes,
             CheckCode::Q002 => CheckCategory::Flake8Quotes,
@@ -1418,6 +1455,7 @@ impl CheckCode {
             CheckCode::S105 => CheckCategory::Flake8Bandit,
             CheckCode::S106 => CheckCategory::Flake8Bandit,
             CheckCode::S107 => CheckCategory::Flake8Bandit,
+            CheckCode::SIM118 => CheckCategory::Flake8Simplify,
             CheckCode::T100 => CheckCategory::Flake8Debugger,
             CheckCode::T201 => CheckCategory::Flake8Print,
             CheckCode::T203 => CheckCategory::Flake8Print,
@@ -1508,23 +1546,28 @@ impl CheckKind {
             CheckKind::TypeComparison => &CheckCode::E721,
             CheckKind::UndefinedExport(_) => &CheckCode::F822,
             CheckKind::UndefinedLocal(_) => &CheckCode::F823,
+            CheckKind::RedefinedWhileUnused(..) => &CheckCode::F811,
             CheckKind::UndefinedName(_) => &CheckCode::F821,
             CheckKind::UnusedImport(..) => &CheckCode::F401,
             CheckKind::UnusedVariable(_) => &CheckCode::F841,
+            CheckKind::UnusedAnnotation(_) => &CheckCode::F842,
             CheckKind::YieldOutsideFunction(_) => &CheckCode::F704,
             // pycodestyle warnings
             CheckKind::NoNewLineAtEndOfFile => &CheckCode::W292,
             CheckKind::InvalidEscapeSequence(_) => &CheckCode::W605,
             // pylint
-            CheckKind::UselessImportAlias => &CheckCode::PLC0414,
-            CheckKind::MisplacedComparisonConstant(..) => &CheckCode::PLC2201,
-            CheckKind::UnnecessaryDirectLambdaCall => &CheckCode::PLC3002,
             CheckKind::AwaitOutsideAsync => &CheckCode::PLE1142,
             CheckKind::ConsiderMergingIsinstance(..) => &CheckCode::PLR1701,
-            CheckKind::PropertyWithParameters => &CheckCode::PLR0206,
             CheckKind::ConsiderUsingFromImport(..) => &CheckCode::PLR0402,
-            CheckKind::ConsiderUsingSysExit => &CheckCode::PLR1722,
+            CheckKind::GlobalVariableNotAssigned(..) => &CheckCode::PLW0602,
+            CheckKind::MisplacedComparisonConstant(..) => &CheckCode::PLC2201,
+            CheckKind::PropertyWithParameters => &CheckCode::PLR0206,
+            CheckKind::UnnecessaryDirectLambdaCall => &CheckCode::PLC3002,
+            CheckKind::UseSysExit(_) => &CheckCode::PLR1722,
+            CheckKind::NonlocalWithoutBinding(..) => &CheckCode::PLE0117,
+            CheckKind::UsedPriorGlobalDeclaration(..) => &CheckCode::PLE0118,
             CheckKind::UselessElseOnLoop => &CheckCode::PLW0120,
+            CheckKind::UselessImportAlias => &CheckCode::PLC0414,
             // flake8-builtins
             CheckKind::BuiltinVariableShadowing(_) => &CheckCode::A001,
             CheckKind::BuiltinArgumentShadowing(_) => &CheckCode::A002,
@@ -1621,6 +1664,8 @@ impl CheckKind {
             CheckKind::SysVersion0Referenced => &CheckCode::YTT301,
             CheckKind::SysVersionCmpStr10 => &CheckCode::YTT302,
             CheckKind::SysVersionSlice1Referenced => &CheckCode::YTT303,
+            // flake8-simplify
+            CheckKind::KeyInDict(..) => &CheckCode::SIM118,
             // pyupgrade
             CheckKind::TypeOfPrimitive(_) => &CheckCode::UP003,
             CheckKind::UselessMetaclassType => &CheckCode::UP001,
@@ -1680,6 +1725,7 @@ impl CheckKind {
             CheckKind::SectionUnderlineMatchesSectionLength(_) => &CheckCode::D409,
             CheckKind::SectionUnderlineNotOverIndented(_) => &CheckCode::D215,
             CheckKind::SkipDocstring => &CheckCode::D418,
+            CheckKind::UsesRPrefixForBackslashedContent => &CheckCode::D301,
             CheckKind::UsesTripleQuotes => &CheckCode::D300,
             // pep8-naming
             CheckKind::InvalidClassName(_) => &CheckCode::N801,
@@ -1846,6 +1892,9 @@ impl CheckKind {
             CheckKind::RaiseNotImplemented => {
                 "`raise NotImplemented` should be `raise NotImplementedError`".to_string()
             }
+            CheckKind::RedefinedWhileUnused(name, line) => {
+                format!("Redefinition of unused `{name}` from line {line}")
+            }
             CheckKind::ReturnOutsideFunction => {
                 "`return` statement outside of a function/method".to_string()
             }
@@ -1894,6 +1943,9 @@ impl CheckKind {
             CheckKind::UndefinedName(name) => {
                 format!("Undefined name `{name}`")
             }
+            CheckKind::UnusedAnnotation(name) => {
+                format!("Local variable `{name}` is annotated but never used")
+            }
             CheckKind::UnusedImport(name, ignore_init) => {
                 if *ignore_init {
                     format!(
@@ -1921,10 +1973,13 @@ impl CheckKind {
             }
             CheckKind::ConsiderMergingIsinstance(obj, types) => {
                 let types = types.join(", ");
-                format!("Consider merging these isinstance calls: `isinstance({obj}, ({types}))`")
+                format!("Merge these isinstance calls: `isinstance({obj}, ({types}))`")
             }
-            CheckKind::MisplacedComparisonConstant(comprison) => {
-                format!("Comparison should be {comprison}")
+            CheckKind::MisplacedComparisonConstant(comparison) => {
+                format!("Comparison should be {comparison}")
+            }
+            CheckKind::NonlocalWithoutBinding(name) => {
+                format!("Nonlocal name `{name}` found without binding")
             }
             CheckKind::UnnecessaryDirectLambdaCall => "Lambda expression called directly. Execute \
                                                        the expression inline instead."
@@ -1933,7 +1988,13 @@ impl CheckKind {
                 "Cannot have defined parameters for properties".to_string()
             }
             CheckKind::ConsiderUsingFromImport(module, name) => {
-                format!("Consider using `from {module} import {name}`")
+                format!("Use `from {module} import {name}` in lieu of alias")
+            }
+            CheckKind::UsedPriorGlobalDeclaration(name, line) => {
+                format!("Name `{name}` is used prior to global declaration on line {line}")
+            }
+            CheckKind::GlobalVariableNotAssigned(name) => {
+                format!("Using global for `{name}` but no assignment is done")
             }
             CheckKind::AwaitOutsideAsync => {
                 "`await` should be used within an async function".to_string()
@@ -1941,7 +2002,7 @@ impl CheckKind {
             CheckKind::UselessElseOnLoop => "Else clause on loop without a break statement, \
                                              remove the else and de-indent all the code inside it"
                 .to_string(),
-            CheckKind::ConsiderUsingSysExit => "Consider using `sys.exit()`".to_string(),
+            CheckKind::UseSysExit(name) => format!("Use `sys.exit()` instead of `{name}`"),
             // flake8-builtins
             CheckKind::BuiltinVariableShadowing(name) => {
                 format!("Variable `{name}` is shadowing a python builtin")
@@ -2271,6 +2332,10 @@ impl CheckKind {
             CheckKind::SysVersionSlice1Referenced => {
                 "`sys.version[:1]` referenced (python10), use `sys.version_info`".to_string()
             }
+            // flake8-simplify
+            CheckKind::KeyInDict(key, dict) => {
+                format!("Use `{key} in {dict}` instead of `{key} in {dict}.keys()`")
+            }
             // pyupgrade
             CheckKind::TypeOfPrimitive(primitive) => {
                 format!("Use `{}` instead of `type(...)`", primitive.builtin())
@@ -2332,6 +2397,9 @@ impl CheckKind {
             CheckKind::FirstLineCapitalized => {
                 "First word of the first line should be properly capitalized".to_string()
             }
+            CheckKind::UsesRPrefixForBackslashedContent => {
+                r#"Use r""" if any backslashes in a docstring"#.to_string()
+            }
             CheckKind::UsesTripleQuotes => r#"Use """triple double quotes""""#.to_string(),
             CheckKind::MultiLineSummaryFirstLine => {
                 "Multi-line docstring summary should start at the first line".to_string()
@@ -2599,7 +2667,6 @@ impl CheckKind {
                 | CheckKind::BlankLineBeforeSection(..)
                 | CheckKind::CapitalizeSectionName(..)
                 | CheckKind::CommentedOutCode
-                | CheckKind::ConsiderUsingSysExit
                 | CheckKind::ConvertNamedTupleFunctionalToClass(..)
                 | CheckKind::ConvertTypedDictFunctionalToClass(..)
                 | CheckKind::DashedUnderlineAfterSection(..)
@@ -2613,6 +2680,7 @@ impl CheckKind {
                 | CheckKind::ImplicitReturn
                 | CheckKind::ImplicitReturnValue
                 | CheckKind::IsLiteral
+                | CheckKind::KeyInDict(..)
                 | CheckKind::MisplacedComparisonConstant(..)
                 | CheckKind::NewLineAfterLastParagraph
                 | CheckKind::NewLineAfterSectionName(..)
@@ -2628,6 +2696,7 @@ impl CheckKind {
                 | CheckKind::NotIsTest
                 | CheckKind::OneBlankLineAfterClass(..)
                 | CheckKind::OneBlankLineBeforeClass(..)
+                | CheckKind::PercentFormatExtraNamedArguments(..)
                 | CheckKind::PEP3120UnnecessaryCodingComment
                 | CheckKind::PPrintFound
                 | CheckKind::PrintFound
@@ -2640,9 +2709,11 @@ impl CheckKind {
                 | CheckKind::SectionUnderlineMatchesSectionLength(..)
                 | CheckKind::SectionUnderlineNotOverIndented(..)
                 | CheckKind::SetAttrWithConstant
+                | CheckKind::StringDotFormatExtraNamedArguments(..)
                 | CheckKind::SuperCallWithParameters
                 | CheckKind::TrueFalseComparison(..)
                 | CheckKind::TypeOfPrimitive(..)
+                | CheckKind::UnnecessaryCallAroundSorted(..)
                 | CheckKind::UnnecessaryCollectionCall(..)
                 | CheckKind::UnnecessaryComprehension(..)
                 | CheckKind::UnnecessaryEncodeUTF8
@@ -2665,6 +2736,7 @@ impl CheckKind {
                 | CheckKind::UnusedNOQA(..)
                 | CheckKind::UsePEP585Annotation(..)
                 | CheckKind::UsePEP604Annotation
+                | CheckKind::UseSysExit(..)
                 | CheckKind::UselessImportAlias
                 | CheckKind::UselessMetaclassType
                 | CheckKind::UselessObjectInheritance(..)

src/checks_gen.rs

@@ -139,6 +139,7 @@ pub enum CheckCodePrefix {
     D3,
     D30,
     D300,
+    D301,
     D4,
     D40,
     D400,
@@ -243,6 +244,8 @@ pub enum CheckCodePrefix {
     F72,
     F722,
     F8,
+    F81,
+    F811,
     F82,
     F821,
     F822,
@@ -251,6 +254,7 @@ pub enum CheckCodePrefix {
     F831,
     F84,
     F841,
+    F842,
     F9,
     F90,
     F901,
@@ -311,6 +315,11 @@ pub enum CheckCodePrefix {
     PLC300,
     PLC3002,
     PLE,
+    PLE0,
+    PLE01,
+    PLE011,
+    PLE0117,
+    PLE0118,
     PLE1,
     PLE11,
     PLE114,
@@ -334,6 +343,9 @@ pub enum CheckCodePrefix {
     PLW01,
     PLW012,
     PLW0120,
+    PLW06,
+    PLW060,
+    PLW0602,
     Q,
     Q0,
     Q00,
@@ -370,6 +382,10 @@ pub enum CheckCodePrefix {
     S105,
     S106,
     S107,
+    SIM,
+    SIM1,
+    SIM11,
+    SIM118,
     T,
     T1,
     T10,
@@ -759,6 +775,7 @@ impl CheckCodePrefix {
                 CheckCode::D214,
                 CheckCode::D215,
                 CheckCode::D300,
+                CheckCode::D301,
                 CheckCode::D400,
                 CheckCode::D402,
                 CheckCode::D403,
@@ -861,9 +878,10 @@ impl CheckCodePrefix {
             CheckCodePrefix::D213 => vec![CheckCode::D213],
             CheckCodePrefix::D214 => vec![CheckCode::D214],
             CheckCodePrefix::D215 => vec![CheckCode::D215],
-            CheckCodePrefix::D3 => vec![CheckCode::D300],
-            CheckCodePrefix::D30 => vec![CheckCode::D300],
+            CheckCodePrefix::D3 => vec![CheckCode::D300, CheckCode::D301],
+            CheckCodePrefix::D30 => vec![CheckCode::D300, CheckCode::D301],
             CheckCodePrefix::D300 => vec![CheckCode::D300],
+            CheckCodePrefix::D301 => vec![CheckCode::D301],
             CheckCodePrefix::D4 => vec![
                 CheckCode::D400,
                 CheckCode::D402,
@@ -1026,11 +1044,13 @@ impl CheckCodePrefix {
                 CheckCode::F706,
                 CheckCode::F707,
                 CheckCode::F722,
+                CheckCode::F811,
                 CheckCode::F821,
                 CheckCode::F822,
                 CheckCode::F823,
                 CheckCode::F831,
                 CheckCode::F841,
+                CheckCode::F842,
                 CheckCode::F901,
             ],
             CheckCodePrefix::F4 => vec![
@@ -1158,20 +1178,25 @@ impl CheckCodePrefix {
             CheckCodePrefix::F72 => vec![CheckCode::F722],
             CheckCodePrefix::F722 => vec![CheckCode::F722],
             CheckCodePrefix::F8 => vec![
+                CheckCode::F811,
                 CheckCode::F821,
                 CheckCode::F822,
                 CheckCode::F823,
                 CheckCode::F831,
                 CheckCode::F841,
+                CheckCode::F842,
             ],
+            CheckCodePrefix::F81 => vec![CheckCode::F811],
+            CheckCodePrefix::F811 => vec![CheckCode::F811],
             CheckCodePrefix::F82 => vec![CheckCode::F821, CheckCode::F822, CheckCode::F823],
             CheckCodePrefix::F821 => vec![CheckCode::F821],
             CheckCodePrefix::F822 => vec![CheckCode::F822],
             CheckCodePrefix::F823 => vec![CheckCode::F823],
             CheckCodePrefix::F83 => vec![CheckCode::F831],
             CheckCodePrefix::F831 => vec![CheckCode::F831],
-            CheckCodePrefix::F84 => vec![CheckCode::F841],
+            CheckCodePrefix::F84 => vec![CheckCode::F841, CheckCode::F842],
             CheckCodePrefix::F841 => vec![CheckCode::F841],
+            CheckCodePrefix::F842 => vec![CheckCode::F842],
             CheckCodePrefix::F9 => vec![CheckCode::F901],
             CheckCodePrefix::F90 => vec![CheckCode::F901],
             CheckCodePrefix::F901 => vec![CheckCode::F901],
@@ -1330,7 +1355,14 @@ impl CheckCodePrefix {
             CheckCodePrefix::PLC30 => vec![CheckCode::PLC3002],
             CheckCodePrefix::PLC300 => vec![CheckCode::PLC3002],
             CheckCodePrefix::PLC3002 => vec![CheckCode::PLC3002],
-            CheckCodePrefix::PLE => vec![CheckCode::PLE1142],
+            CheckCodePrefix::PLE => {
+                vec![CheckCode::PLE0117, CheckCode::PLE0118, CheckCode::PLE1142]
+            }
+            CheckCodePrefix::PLE0 => vec![CheckCode::PLE0117, CheckCode::PLE0118],
+            CheckCodePrefix::PLE01 => vec![CheckCode::PLE0117, CheckCode::PLE0118],
+            CheckCodePrefix::PLE011 => vec![CheckCode::PLE0117, CheckCode::PLE0118],
+            CheckCodePrefix::PLE0117 => vec![CheckCode::PLE0117],
+            CheckCodePrefix::PLE0118 => vec![CheckCode::PLE0118],
             CheckCodePrefix::PLE1 => vec![CheckCode::PLE1142],
             CheckCodePrefix::PLE11 => vec![CheckCode::PLE1142],
             CheckCodePrefix::PLE114 => vec![CheckCode::PLE1142],
@@ -1354,11 +1386,14 @@ impl CheckCodePrefix {
             CheckCodePrefix::PLR1701 => vec![CheckCode::PLR1701],
             CheckCodePrefix::PLR172 => vec![CheckCode::PLR1722],
             CheckCodePrefix::PLR1722 => vec![CheckCode::PLR1722],
-            CheckCodePrefix::PLW => vec![CheckCode::PLW0120],
-            CheckCodePrefix::PLW0 => vec![CheckCode::PLW0120],
+            CheckCodePrefix::PLW => vec![CheckCode::PLW0120, CheckCode::PLW0602],
+            CheckCodePrefix::PLW0 => vec![CheckCode::PLW0120, CheckCode::PLW0602],
             CheckCodePrefix::PLW01 => vec![CheckCode::PLW0120],
             CheckCodePrefix::PLW012 => vec![CheckCode::PLW0120],
             CheckCodePrefix::PLW0120 => vec![CheckCode::PLW0120],
+            CheckCodePrefix::PLW06 => vec![CheckCode::PLW0602],
+            CheckCodePrefix::PLW060 => vec![CheckCode::PLW0602],
+            CheckCodePrefix::PLW0602 => vec![CheckCode::PLW0602],
             CheckCodePrefix::Q => vec![
                 CheckCode::Q000,
                 CheckCode::Q001,
@@ -1463,6 +1498,10 @@ impl CheckCodePrefix {
             CheckCodePrefix::S105 => vec![CheckCode::S105],
             CheckCodePrefix::S106 => vec![CheckCode::S106],
             CheckCodePrefix::S107 => vec![CheckCode::S107],
+            CheckCodePrefix::SIM => vec![CheckCode::SIM118],
+            CheckCodePrefix::SIM1 => vec![CheckCode::SIM118],
+            CheckCodePrefix::SIM11 => vec![CheckCode::SIM118],
+            CheckCodePrefix::SIM118 => vec![CheckCode::SIM118],
             CheckCodePrefix::T => vec![CheckCode::T100, CheckCode::T201, CheckCode::T203],
             CheckCodePrefix::T1 => vec![CheckCode::T100],
             CheckCodePrefix::T10 => vec![CheckCode::T100],
@@ -1929,6 +1968,7 @@ impl CheckCodePrefix {
             CheckCodePrefix::D3 => SuffixLength::One,
             CheckCodePrefix::D30 => SuffixLength::Two,
             CheckCodePrefix::D300 => SuffixLength::Three,
+            CheckCodePrefix::D301 => SuffixLength::Three,
             CheckCodePrefix::D4 => SuffixLength::One,
             CheckCodePrefix::D40 => SuffixLength::Two,
             CheckCodePrefix::D400 => SuffixLength::Three,
@@ -2033,6 +2073,8 @@ impl CheckCodePrefix {
             CheckCodePrefix::F72 => SuffixLength::Two,
             CheckCodePrefix::F722 => SuffixLength::Three,
             CheckCodePrefix::F8 => SuffixLength::One,
+            CheckCodePrefix::F81 => SuffixLength::Two,
+            CheckCodePrefix::F811 => SuffixLength::Three,
             CheckCodePrefix::F82 => SuffixLength::Two,
             CheckCodePrefix::F821 => SuffixLength::Three,
             CheckCodePrefix::F822 => SuffixLength::Three,
@@ -2041,6 +2083,7 @@ impl CheckCodePrefix {
             CheckCodePrefix::F831 => SuffixLength::Three,
             CheckCodePrefix::F84 => SuffixLength::Two,
             CheckCodePrefix::F841 => SuffixLength::Three,
+            CheckCodePrefix::F842 => SuffixLength::Three,
             CheckCodePrefix::F9 => SuffixLength::One,
             CheckCodePrefix::F90 => SuffixLength::Two,
             CheckCodePrefix::F901 => SuffixLength::Three,
@@ -2101,6 +2144,11 @@ impl CheckCodePrefix {
             CheckCodePrefix::PLC300 => SuffixLength::Three,
             CheckCodePrefix::PLC3002 => SuffixLength::Four,
             CheckCodePrefix::PLE => SuffixLength::Zero,
+            CheckCodePrefix::PLE0 => SuffixLength::One,
+            CheckCodePrefix::PLE01 => SuffixLength::Two,
+            CheckCodePrefix::PLE011 => SuffixLength::Three,
+            CheckCodePrefix::PLE0117 => SuffixLength::Four,
+            CheckCodePrefix::PLE0118 => SuffixLength::Four,
             CheckCodePrefix::PLE1 => SuffixLength::One,
             CheckCodePrefix::PLE11 => SuffixLength::Two,
             CheckCodePrefix::PLE114 => SuffixLength::Three,
@@ -2124,6 +2172,9 @@ impl CheckCodePrefix {
             CheckCodePrefix::PLW01 => SuffixLength::Two,
             CheckCodePrefix::PLW012 => SuffixLength::Three,
             CheckCodePrefix::PLW0120 => SuffixLength::Four,
+            CheckCodePrefix::PLW06 => SuffixLength::Two,
+            CheckCodePrefix::PLW060 => SuffixLength::Three,
+            CheckCodePrefix::PLW0602 => SuffixLength::Four,
             CheckCodePrefix::Q => SuffixLength::Zero,
             CheckCodePrefix::Q0 => SuffixLength::One,
             CheckCodePrefix::Q00 => SuffixLength::Two,
@@ -2160,6 +2211,10 @@ impl CheckCodePrefix {
             CheckCodePrefix::S105 => SuffixLength::Three,
             CheckCodePrefix::S106 => SuffixLength::Three,
             CheckCodePrefix::S107 => SuffixLength::Three,
+            CheckCodePrefix::SIM => SuffixLength::Zero,
+            CheckCodePrefix::SIM1 => SuffixLength::One,
+            CheckCodePrefix::SIM11 => SuffixLength::Two,
+            CheckCodePrefix::SIM118 => SuffixLength::Three,
             CheckCodePrefix::T => SuffixLength::Zero,
             CheckCodePrefix::T1 => SuffixLength::One,
             CheckCodePrefix::T10 => SuffixLength::Two,
@@ -2260,6 +2315,7 @@ pub const CATEGORIES: &[CheckCodePrefix] = &[
     CheckCodePrefix::RET,
     CheckCodePrefix::RUF,
     CheckCodePrefix::S,
+    CheckCodePrefix::SIM,
     CheckCodePrefix::T,
     CheckCodePrefix::TID,
     CheckCodePrefix::UP,

src/cli.rs

@@ -1,4 +1,4 @@
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 
 use clap::{command, Parser};
 use regex::Regex;
@@ -6,6 +6,7 @@ use rustc_hash::FxHashMap;
 
 use crate::checks::CheckCode;
 use crate::checks_gen::CheckCodePrefix;
+use crate::fs;
 use crate::logging::LogLevel;
 use crate::settings::types::{
     FilePattern, PatternPrefixPair, PerFileIgnore, PythonVersion, SerializationFormat,
@@ -47,46 +48,48 @@ pub struct Cli {
     pub no_cache: bool,
     /// List of error codes to enable.
     #[arg(long, value_delimiter = ',')]
-    pub select: Vec<CheckCodePrefix>,
+    pub select: Option<Vec<CheckCodePrefix>>,
     /// Like --select, but adds additional error codes on top of the selected
     /// ones.
     #[arg(long, value_delimiter = ',')]
-    pub extend_select: Vec<CheckCodePrefix>,
+    pub extend_select: Option<Vec<CheckCodePrefix>>,
     /// List of error codes to ignore.
     #[arg(long, value_delimiter = ',')]
-    pub ignore: Vec<CheckCodePrefix>,
+    pub ignore: Option<Vec<CheckCodePrefix>>,
     /// Like --ignore, but adds additional error codes on top of the ignored
     /// ones.
     #[arg(long, value_delimiter = ',')]
-    pub extend_ignore: Vec<CheckCodePrefix>,
+    pub extend_ignore: Option<Vec<CheckCodePrefix>>,
     /// List of paths, used to exclude files and/or directories from checks.
     #[arg(long, value_delimiter = ',')]
-    pub exclude: Vec<FilePattern>,
+    pub exclude: Option<Vec<FilePattern>>,
     /// Like --exclude, but adds additional files and directories on top of the
     /// excluded ones.
     #[arg(long, value_delimiter = ',')]
-    pub extend_exclude: Vec<FilePattern>,
+    pub extend_exclude: Option<Vec<FilePattern>>,
     /// List of error codes to treat as eligible for autofix. Only applicable
     /// when autofix itself is enabled (e.g., via `--fix`).
     #[arg(long, value_delimiter = ',')]
-    pub fixable: Vec<CheckCodePrefix>,
+    pub fixable: Option<Vec<CheckCodePrefix>>,
     /// List of error codes to treat as ineligible for autofix. Only applicable
     /// when autofix itself is enabled (e.g., via `--fix`).
     #[arg(long, value_delimiter = ',')]
-    pub unfixable: Vec<CheckCodePrefix>,
+    pub unfixable: Option<Vec<CheckCodePrefix>>,
     /// List of mappings from file pattern to code to exclude
     #[arg(long, value_delimiter = ',')]
-    pub per_file_ignores: Vec<PatternPrefixPair>,
+    pub per_file_ignores: Option<Vec<PatternPrefixPair>>,
     /// Output serialization format for error messages.
     #[arg(long, value_enum)]
     pub format: Option<SerializationFormat>,
     /// Show violations with source code.
-    #[arg(long)]
-    pub show_source: bool,
+    #[arg(long, overrides_with("no_show_source"))]
+    show_source: bool,
+    #[clap(long, overrides_with("show_source"), hide = true)]
+    no_show_source: bool,
     /// See the files Ruff will be run against with the current settings.
     #[arg(long)]
     pub show_files: bool,
-    /// See Ruff's settings.
+    /// See the settings Ruff used for the first matching file.
     #[arg(long)]
     pub show_settings: bool,
     /// Enable automatic additions of noqa directives to failing lines.
@@ -121,9 +124,47 @@ pub struct Cli {
 }
 
 impl Cli {
-    // See: https://github.com/clap-rs/clap/issues/3146
-    pub fn fix(&self) -> Option<bool> {
-        resolve_bool_arg(self.fix, self.no_fix)
+    /// Partition the CLI into command-line arguments and configuration
+    /// overrides.
+    pub fn partition(self) -> (Arguments, Overrides) {
+        (
+            Arguments {
+                add_noqa: self.add_noqa,
+                autoformat: self.autoformat,
+                config: self.config,
+                exit_zero: self.exit_zero,
+                explain: self.explain,
+                files: self.files,
+                generate_shell_completion: self.generate_shell_completion,
+                no_cache: self.no_cache,
+                quiet: self.quiet,
+                show_files: self.show_files,
+                show_settings: self.show_settings,
+                silent: self.silent,
+                stdin_filename: self.stdin_filename,
+                verbose: self.verbose,
+                watch: self.watch,
+            },
+            Overrides {
+                dummy_variable_rgx: self.dummy_variable_rgx,
+                exclude: self.exclude,
+                extend_exclude: self.extend_exclude,
+                extend_ignore: self.extend_ignore,
+                extend_select: self.extend_select,
+                fixable: self.fixable,
+                ignore: self.ignore,
+                line_length: self.line_length,
+                max_complexity: self.max_complexity,
+                per_file_ignores: self.per_file_ignores,
+                select: self.select,
+                show_source: resolve_bool_arg(self.show_source, self.no_show_source),
+                target_version: self.target_version,
+                unfixable: self.unfixable,
+                // TODO(charlie): Included in `pyproject.toml`, but not inherited.
+                fix: resolve_bool_arg(self.fix, self.no_fix),
+                format: self.format,
+            },
+        )
     }
 }
 
@@ -136,8 +177,52 @@ fn resolve_bool_arg(yes: bool, no: bool) -> Option<bool> {
     }
 }
 
+/// CLI settings that are distinct from configuration (commands, lists of files,
+/// etc.).
+#[allow(clippy::struct_excessive_bools)]
+pub struct Arguments {
+    pub add_noqa: bool,
+    pub autoformat: bool,
+    pub config: Option<PathBuf>,
+    pub exit_zero: bool,
+    pub explain: Option<CheckCode>,
+    pub files: Vec<PathBuf>,
+    pub generate_shell_completion: Option<clap_complete_command::Shell>,
+    pub no_cache: bool,
+    pub quiet: bool,
+    pub show_files: bool,
+    pub show_settings: bool,
+    pub silent: bool,
+    pub stdin_filename: Option<String>,
+    pub verbose: bool,
+    pub watch: bool,
+}
+
+/// CLI settings that function as configuration overrides.
+#[derive(Clone)]
+#[allow(clippy::struct_excessive_bools)]
+pub struct Overrides {
+    pub dummy_variable_rgx: Option<Regex>,
+    pub exclude: Option<Vec<FilePattern>>,
+    pub extend_exclude: Option<Vec<FilePattern>>,
+    pub extend_ignore: Option<Vec<CheckCodePrefix>>,
+    pub extend_select: Option<Vec<CheckCodePrefix>>,
+    pub fixable: Option<Vec<CheckCodePrefix>>,
+    pub ignore: Option<Vec<CheckCodePrefix>>,
+    pub line_length: Option<usize>,
+    pub max_complexity: Option<usize>,
+    pub per_file_ignores: Option<Vec<PatternPrefixPair>>,
+    pub select: Option<Vec<CheckCodePrefix>>,
+    pub show_source: Option<bool>,
+    pub target_version: Option<PythonVersion>,
+    pub unfixable: Option<Vec<CheckCodePrefix>>,
+    // TODO(charlie): Captured in pyproject.toml as a default, but not part of `Settings`.
+    pub fix: Option<bool>,
+    pub format: Option<SerializationFormat>,
+}
+
 /// Map the CLI settings to a `LogLevel`.
-pub fn extract_log_level(cli: &Cli) -> LogLevel {
+pub fn extract_log_level(cli: &Arguments) -> LogLevel {
     if cli.silent {
         LogLevel::Silent
     } else if cli.quiet {
@@ -160,6 +245,9 @@ pub fn collect_per_file_ignores(pairs: Vec<PatternPrefixPair>) -> Vec<PerFileIgn
     }
     per_file_ignores
         .into_iter()
-        .map(|(pattern, prefixes)| PerFileIgnore::new(pattern, &prefixes))
+        .map(|(pattern, prefixes)| {
+            let absolute = fs::normalize_path(Path::new(&pattern));
+            PerFileIgnore::new(pattern, absolute, &prefixes)
+        })
         .collect()
 }

src/commands.rs

@@ -1,36 +1,207 @@
-use std::path::PathBuf;
+use std::io::{self, Read};
+use std::path::{Path, PathBuf};
+use std::time::Instant;
 
 use anyhow::{bail, Result};
+use itertools::Itertools;
+use log::{debug, error};
+#[cfg(not(target_family = "wasm"))]
+use rayon::prelude::*;
+use rustpython_ast::Location;
 use serde::Serialize;
-use walkdir::DirEntry;
 
-use crate::checks::CheckCode;
-use crate::fs::iter_python_files;
+use crate::autofix::fixer;
+use crate::checks::{CheckCode, CheckKind};
+use crate::cli::Overrides;
+use crate::iterators::par_iter;
+use crate::linter::{add_noqa_to_path, autoformat_path, lint_path, lint_stdin, Diagnostics};
+use crate::message::Message;
+use crate::resolver;
+use crate::resolver::Strategy;
 use crate::settings::types::SerializationFormat;
-use crate::{Configuration, Settings};
+
+/// Run the linter over a collection of files.
+pub fn run(
+    files: &[PathBuf],
+    strategy: &Strategy,
+    overrides: &Overrides,
+    cache: bool,
+    autofix: &fixer::Mode,
+) -> Result<Diagnostics> {
+    // Collect all the files to check.
+    let start = Instant::now();
+    let (paths, resolver) = resolver::resolve_python_files(files, strategy, overrides)?;
+    let duration = start.elapsed();
+    debug!("Identified files to lint in: {:?}", duration);
+
+    let start = Instant::now();
+    let mut diagnostics: Diagnostics = par_iter(&paths)
+        .map(|entry| {
+            match entry {
+                Ok(entry) => {
+                    let path = entry.path();
+                    let settings = resolver.resolve(path, strategy);
+                    lint_path(path, settings, &cache.into(), autofix)
+                        .map_err(|e| (Some(path.to_owned()), e.to_string()))
+                }
+                Err(e) => Err((
+                    e.path().map(Path::to_owned),
+                    e.io_error()
+                        .map_or_else(|| e.to_string(), io::Error::to_string),
+                )),
+            }
+            .unwrap_or_else(|(path, message)| {
+                if let Some(path) = &path {
+                    let settings = resolver.resolve(path, strategy);
+                    if settings.enabled.contains(&CheckCode::E902) {
+                        Diagnostics::new(vec![Message {
+                            kind: CheckKind::IOError(message),
+                            location: Location::default(),
+                            end_location: Location::default(),
+                            fix: None,
+                            filename: path.to_string_lossy().to_string(),
+                            source: None,
+                        }])
+                    } else {
+                        error!("Failed to check {}: {message}", path.to_string_lossy());
+                        Diagnostics::default()
+                    }
+                } else {
+                    error!("{message}");
+                    Diagnostics::default()
+                }
+            })
+        })
+        .reduce(Diagnostics::default, |mut acc, item| {
+            acc += item;
+            acc
+        });
+
+    diagnostics.messages.sort_unstable();
+    let duration = start.elapsed();
+    debug!("Checked files in: {:?}", duration);
+
+    Ok(diagnostics)
+}
+
+/// Read a `String` from `stdin`.
+fn read_from_stdin() -> Result<String> {
+    let mut buffer = String::new();
+    io::stdin().lock().read_to_string(&mut buffer)?;
+    Ok(buffer)
+}
+
+/// Run the linter over a single file, read from `stdin`.
+pub fn run_stdin(
+    strategy: &Strategy,
+    filename: &Path,
+    autofix: &fixer::Mode,
+) -> Result<Diagnostics> {
+    let stdin = read_from_stdin()?;
+    let settings = match strategy {
+        Strategy::Fixed(settings) => settings,
+        Strategy::Hierarchical(settings) => settings,
+    };
+    let mut diagnostics = lint_stdin(filename, &stdin, settings, autofix)?;
+    diagnostics.messages.sort_unstable();
+    Ok(diagnostics)
+}
+
+/// Add `noqa` directives to a collection of files.
+pub fn add_noqa(files: &[PathBuf], strategy: &Strategy, overrides: &Overrides) -> Result<usize> {
+    // Collect all the files to check.
+    let start = Instant::now();
+    let (paths, resolver) = resolver::resolve_python_files(files, strategy, overrides)?;
+    let duration = start.elapsed();
+    debug!("Identified files to lint in: {:?}", duration);
+
+    let start = Instant::now();
+    let modifications: usize = par_iter(&paths)
+        .flatten()
+        .filter_map(|entry| {
+            let path = entry.path();
+            let settings = resolver.resolve(path, strategy);
+            match add_noqa_to_path(path, settings) {
+                Ok(count) => Some(count),
+                Err(e) => {
+                    error!("Failed to add noqa to {}: {e}", path.to_string_lossy());
+                    None
+                }
+            }
+        })
+        .sum();
+
+    let duration = start.elapsed();
+    debug!("Added noqa to files in: {:?}", duration);
+
+    Ok(modifications)
+}
+
+/// Automatically format a collection of files.
+pub fn autoformat(files: &[PathBuf], strategy: &Strategy, overrides: &Overrides) -> Result<usize> {
+    // Collect all the files to format.
+    let start = Instant::now();
+    let (paths, resolver) = resolver::resolve_python_files(files, strategy, overrides)?;
+    let duration = start.elapsed();
+    debug!("Identified files to lint in: {:?}", duration);
+
+    let start = Instant::now();
+    let modifications = par_iter(&paths)
+        .flatten()
+        .filter_map(|entry| {
+            let path = entry.path();
+            let settings = resolver.resolve(path, strategy);
+            match autoformat_path(path, settings) {
+                Ok(()) => Some(()),
+                Err(e) => {
+                    error!("Failed to autoformat {}: {e}", path.to_string_lossy());
+                    None
+                }
+            }
+        })
+        .count();
+
+    let duration = start.elapsed();
+    debug!("Auto-formatted files in: {:?}", duration);
+
+    Ok(modifications)
+}
 
 /// Print the user-facing configuration settings.
-pub fn show_settings(
-    configuration: &Configuration,
-    project_root: Option<&PathBuf>,
-    pyproject: Option<&PathBuf>,
-) {
-    println!("Resolved configuration: {configuration:#?}");
-    println!("Found project root at: {project_root:?}");
-    println!("Found pyproject.toml at: {pyproject:?}");
+pub fn show_settings(files: &[PathBuf], strategy: &Strategy, overrides: &Overrides) -> Result<()> {
+    // Collect all files in the hierarchy.
+    let (paths, resolver) = resolver::resolve_python_files(files, strategy, overrides)?;
+
+    // Print the list of files.
+    let Some(entry) = paths
+        .iter()
+        .flatten()
+        .sorted_by(|a, b| a.path().cmp(b.path())).next() else {
+        bail!("No files found under the given path");
+    };
+    let path = entry.path();
+    let settings = resolver.resolve(path, strategy);
+    println!("Resolved settings for: {path:?}");
+    println!("{settings:#?}");
+
+    Ok(())
 }
 
 /// Show the list of files to be checked based on current settings.
-pub fn show_files(files: &[PathBuf], settings: &Settings) {
-    let mut entries: Vec<DirEntry> = files
+pub fn show_files(files: &[PathBuf], strategy: &Strategy, overrides: &Overrides) -> Result<()> {
+    // Collect all files in the hierarchy.
+    let (paths, _resolver) = resolver::resolve_python_files(files, strategy, overrides)?;
+
+    // Print the list of files.
+    for entry in paths
         .iter()
-        .flat_map(|path| iter_python_files(path, &settings.exclude, &settings.extend_exclude))
         .flatten()
-        .collect();
-    entries.sort_by(|a, b| a.path().cmp(b.path()));
-    for entry in entries {
+        .sorted_by(|a, b| a.path().cmp(b.path()))
+    {
         println!("{}", entry.path().to_string_lossy());
     }
+
+    Ok(())
 }
 
 #[derive(Serialize)]
@@ -41,7 +212,7 @@ struct Explanation<'a> {
 }
 
 /// Explain a `CheckCode` to the user.
-pub fn explain(code: &CheckCode, format: SerializationFormat) -> Result<()> {
+pub fn explain(code: &CheckCode, format: &SerializationFormat) -> Result<()> {
     match format {
         SerializationFormat::Text | SerializationFormat::Grouped => {
             println!(

src/docstrings/constants.rs

@@ -1,5 +1,9 @@
 pub const TRIPLE_QUOTE_PREFIXES: &[&str] = &[
-    "ur\"\"\"", "ur'''", "u\"\"\"", "u'''", "r\"\"\"", "r'''", "\"\"\"", "'''",
+    "ur\"\"\"", "ur'''", "u\"\"\"", "u'''", "r\"\"\"", "r'''", "UR\"\"\"", "UR'''", "Ur\"\"\"",
+    "Ur'''", "U\"\"\"", "U'''", "uR\"\"\"", "uR'''", "R\"\"\"", "R'''", "\"\"\"", "'''",
 ];
 
-pub const SINGLE_QUOTE_PREFIXES: &[&str] = &["ur\"", "ur'", "u\"", "u'", "r\"", "r'", "\"", "'"];
+pub const SINGLE_QUOTE_PREFIXES: &[&str] = &[
+    "ur\"", "ur'", "u\"", "u'", "r\"", "r'", "ur\"", "ur'", "u\"", "u'", "r\"", "r'", "UR\"",
+    "UR'", "Ur\"", "Ur'", "U\"", "U'", "uR\"", "uR'", "R\"", "R'", "\"", "'",
+];

src/docstrings/definition.rs

@@ -1,6 +1,8 @@
+use std::borrow::Cow;
+
 use rustpython_ast::{Expr, Stmt};
 
-#[derive(Debug)]
+#[derive(Debug, Clone)]
 pub enum DefinitionKind<'a> {
     Module,
     Package,
@@ -17,6 +19,15 @@ pub struct Definition<'a> {
     pub docstring: Option<&'a Expr>,
 }
 
+#[derive(Debug)]
+pub struct Docstring<'a> {
+    pub kind: DefinitionKind<'a>,
+    pub expr: &'a Expr,
+    pub contents: &'a Cow<'a, str>,
+    pub body: &'a str,
+    pub indentation: &'a Cow<'a, str>,
+}
+
 pub enum Documentable {
     Class,
     Function,

src/docstrings/sections.rs

@@ -3,7 +3,7 @@ use crate::docstrings::styles::SectionStyle;
 
 #[derive(Debug)]
 pub(crate) struct SectionContext<'a> {
-    pub(crate) section_name: String,
+    pub(crate) section_name: &'a str,
     pub(crate) previous_line: &'a str,
     pub(crate) line: &'a str,
     pub(crate) following_lines: &'a [&'a str],
@@ -22,7 +22,7 @@ fn is_docstring_section(context: &SectionContext) -> bool {
     let section_name_suffix = context
         .line
         .trim()
-        .strip_prefix(&context.section_name)
+        .strip_prefix(context.section_name)
         .unwrap()
         .trim();
     let this_looks_like_a_section_name =

src/eradicate/detection.rs

@@ -4,7 +4,7 @@ use regex::Regex;
 
 static ALLOWLIST_REGEX: Lazy<Regex> = Lazy::new(|| {
     Regex::new(
-        r"(?i)pylint|pyright|noqa|nosec|type:\s*ignore|fmt:\s*(on|off)|isort:\s*(on|off|skip|skip_file|split|dont-add-imports(:\s*\[.*?])?)|TODO|FIXME|XXX"
+        r"^(?i)(?:pylint|pyright|noqa|nosec|type:\s*ignore|fmt:\s*(on|off)|isort:\s*(on|off|skip|skip_file|split|dont-add-imports(:\s*\[.*?])?)|TODO|FIXME|XXX)"
     ).unwrap()
 });
 static BRACKET_REGEX: Lazy<Regex> = Lazy::new(|| Regex::new(r"^[()\[\]{}\s]+$").unwrap());

src/flake8_print/plugins/print_call.rs

@@ -19,24 +19,14 @@ pub fn print_call(checker: &mut Checker, expr: &Expr, func: &Expr) {
     };
 
     if checker.patch(check.kind.code()) {
-        let context = checker.binding_context();
-        if matches!(
-            checker.parents[context.defined_by].node,
-            StmtKind::Expr { .. }
-        ) {
-            let deleted: Vec<&Stmt> = checker
-                .deletions
-                .iter()
-                .map(|index| checker.parents[*index])
-                .collect();
-            match helpers::remove_stmt(
-                checker.parents[context.defined_by],
-                context.defined_in.map(|index| checker.parents[index]),
-                &deleted,
-            ) {
+        let defined_by = checker.current_parent();
+        let defined_in = checker.current_grandparent();
+        if matches!(defined_by.0.node, StmtKind::Expr { .. }) {
+            let deleted: Vec<&Stmt> = checker.deletions.iter().map(|node| node.0).collect();
+            match helpers::remove_stmt(defined_by.0, defined_in.map(|node| node.0), &deleted) {
                 Ok(fix) => {
                     if fix.content.is_empty() || fix.content == "pass" {
-                        checker.deletions.insert(context.defined_by);
+                        checker.deletions.insert(defined_by.clone());
                     }
                     check.amend(fix);
                 }

src/flake8_return/visitor.rs

@@ -18,6 +18,8 @@ pub struct Stack<'a> {
 #[derive(Default)]
 pub struct ReturnVisitor<'a> {
     pub stack: Stack<'a>,
+    // If we're in an f-string, the location of the defining expression.
+    in_f_string: Option<Location>,
 }
 
 impl<'a> ReturnVisitor<'a> {
@@ -34,7 +36,7 @@ impl<'a> ReturnVisitor<'a> {
                     .assigns
                     .entry(id)
                     .or_insert_with(Vec::new)
-                    .push(expr.location);
+                    .push(self.in_f_string.unwrap_or(expr.location));
                 return;
             }
             _ => {}
@@ -70,7 +72,7 @@ impl<'a> Visitor<'a> for ReturnVisitor<'a> {
                         .refs
                         .entry(id)
                         .or_insert_with(Vec::new)
-                        .push(value.location);
+                        .push(self.in_f_string.unwrap_or(value.location));
                 }
 
                 visitor::walk_expr(self, value);
@@ -111,7 +113,13 @@ impl<'a> Visitor<'a> for ReturnVisitor<'a> {
                     .refs
                     .entry(id)
                     .or_insert_with(Vec::new)
-                    .push(expr.location);
+                    .push(self.in_f_string.unwrap_or(expr.location));
+            }
+            ExprKind::JoinedStr { .. } => {
+                let prev_in_f_string = self.in_f_string;
+                self.in_f_string = Some(expr.location);
+                visitor::walk_expr(self, expr);
+                self.in_f_string = prev_in_f_string;
             }
             _ => visitor::walk_expr(self, expr),
         }

src/flake8_simplify/mod.rs

@@ -0,0 +1,29 @@
+pub mod plugins;
+
+#[cfg(test)]
+mod tests {
+    use std::convert::AsRef;
+    use std::path::Path;
+
+    use anyhow::Result;
+    use test_case::test_case;
+
+    use crate::checks::CheckCode;
+    use crate::linter::test_path;
+    use crate::settings;
+
+    #[test_case(CheckCode::SIM118, Path::new("SIM118.py"); "SIM118")]
+    fn checks(check_code: CheckCode, path: &Path) -> Result<()> {
+        let snapshot = format!("{}_{}", check_code.as_ref(), path.to_string_lossy());
+        let mut checks = test_path(
+            Path::new("./resources/test/fixtures/flake8_simplify")
+                .join(path)
+                .as_path(),
+            &settings::Settings::for_rule(check_code),
+            true,
+        )?;
+        checks.sort_by_key(|check| check.location);
+        insta::assert_yaml_snapshot!(snapshot, checks);
+        Ok(())
+    }
+}

src/flake8_simplify/plugins/key_in_dict.rs

@@ -0,0 +1,74 @@
+use rustpython_ast::{Cmpop, Expr, ExprKind};
+
+use crate::ast::types::Range;
+use crate::autofix::Fix;
+use crate::check_ast::Checker;
+use crate::checks::{Check, CheckCode, CheckKind};
+
+/// SIM118
+fn key_in_dict(checker: &mut Checker, left: &Expr, right: &Expr, range: Range) {
+    let ExprKind::Call {
+        func,
+        args,
+        keywords,
+    } = &right.node else {
+        return;
+    };
+    if !(args.is_empty() && keywords.is_empty()) {
+        return;
+    }
+
+    let ExprKind::Attribute { attr, value, .. } = &func.node else {
+        return;
+    };
+    if attr != "keys" {
+        return;
+    }
+
+    let mut check = Check::new(
+        CheckKind::KeyInDict(left.to_string(), value.to_string()),
+        range,
+    );
+    if checker.patch(&CheckCode::SIM118) {
+        let content = right.to_string().replace(".keys()", "");
+        check.amend(Fix::replacement(
+            content,
+            right.location,
+            right.end_location.unwrap(),
+        ));
+    }
+    checker.add_check(check);
+}
+
+/// SIM118 in a for loop
+pub fn key_in_dict_for(checker: &mut Checker, target: &Expr, iter: &Expr) {
+    key_in_dict(
+        checker,
+        target,
+        iter,
+        Range {
+            location: target.location,
+            end_location: iter.end_location.unwrap(),
+        },
+    );
+}
+
+/// SIM118 in a comparison
+pub fn key_in_dict_compare(
+    checker: &mut Checker,
+    expr: &Expr,
+    left: &Expr,
+    ops: &[Cmpop],
+    comparators: &[Expr],
+) {
+    if !matches!(ops[..], [Cmpop::In]) {
+        return;
+    }
+
+    if comparators.len() != 1 {
+        return;
+    }
+    let right = comparators.first().unwrap();
+
+    key_in_dict(checker, left, right, Range::from_located(expr));
+}

src/flake8_simplify/plugins/mod.rs

@@ -0,0 +1,3 @@
+pub use key_in_dict::{key_in_dict_compare, key_in_dict_for};
+
+mod key_in_dict;

src/flake8_simplify/snapshots/ruff__flake8_simplify__tests__SIM118_SIM118.py.snap

@@ -0,0 +1,77 @@
+---
+source: src/flake8_simplify/mod.rs
+expression: checks
+---
+- kind:
+    KeyInDict:
+      - key
+      - dict
+  location:
+    row: 1
+    column: 0
+  end_location:
+    row: 1
+    column: 18
+  fix:
+    content: dict
+    location:
+      row: 1
+      column: 7
+    end_location:
+      row: 1
+      column: 18
+- kind:
+    KeyInDict:
+      - "foo['bar']"
+      - dict
+  location:
+    row: 3
+    column: 0
+  end_location:
+    row: 3
+    column: 25
+  fix:
+    content: dict
+    location:
+      row: 3
+      column: 14
+    end_location:
+      row: 3
+      column: 25
+- kind:
+    KeyInDict:
+      - foo()
+      - dict
+  location:
+    row: 5
+    column: 0
+  end_location:
+    row: 5
+    column: 20
+  fix:
+    content: dict
+    location:
+      row: 5
+      column: 9
+    end_location:
+      row: 5
+      column: 20
+- kind:
+    KeyInDict:
+      - key
+      - dict
+  location:
+    row: 7
+    column: 4
+  end_location:
+    row: 7
+    column: 22
+  fix:
+    content: dict
+    location:
+      row: 7
+      column: 11
+    end_location:
+      row: 7
+      column: 22
+

src/flake8_unused_arguments/plugins.rs

@@ -17,12 +17,13 @@ use crate::{visibility, Check};
 fn function(
     argumentable: &Argumentable,
     args: &Arguments,
-    bindings: &FxHashMap<&str, Binding>,
+    values: &FxHashMap<&str, usize>,
+    bindings: &[Binding],
     dummy_variable_rgx: &Regex,
 ) -> Vec<Check> {
     let mut checks: Vec<Check> = vec![];
     for arg_name in collect_arg_names(args) {
-        if let Some(binding) = bindings.get(arg_name) {
+        if let Some(binding) = values.get(arg_name).map(|index| &bindings[*index]) {
             if binding.used.is_none()
                 && matches!(binding.kind, BindingKind::Argument)
                 && !dummy_variable_rgx.is_match(arg_name)
@@ -41,7 +42,8 @@ fn function(
 fn method(
     argumentable: &Argumentable,
     args: &Arguments,
-    bindings: &FxHashMap<&str, Binding>,
+    values: &FxHashMap<&str, usize>,
+    bindings: &[Binding],
     dummy_variable_rgx: &Regex,
 ) -> Vec<Check> {
     let mut checks: Vec<Check> = vec![];
@@ -54,7 +56,10 @@ fn method(
         .chain(iter::once::<Option<&Arg>>(args.vararg.as_deref()).flatten())
         .chain(iter::once::<Option<&Arg>>(args.kwarg.as_deref()).flatten())
     {
-        if let Some(binding) = bindings.get(&arg.node.arg.as_str()) {
+        if let Some(binding) = values
+            .get(&arg.node.arg.as_str())
+            .map(|index| &bindings[*index])
+        {
             if binding.used.is_none()
                 && matches!(binding.kind, BindingKind::Argument)
                 && !dummy_variable_rgx.is_match(arg.node.arg.as_str())
@@ -70,7 +75,12 @@ fn method(
 }
 
 /// ARG001, ARG002, ARG003, ARG004, ARG005
-pub fn unused_arguments(checker: &Checker, parent: &Scope, scope: &Scope) -> Vec<Check> {
+pub fn unused_arguments(
+    checker: &Checker,
+    parent: &Scope,
+    scope: &Scope,
+    bindings: &[Binding],
+) -> Vec<Check> {
     match &scope.kind {
         ScopeKind::Function(FunctionDef {
             name,
@@ -98,6 +108,7 @@ pub fn unused_arguments(checker: &Checker, parent: &Scope, scope: &Scope) -> Vec
                             &Argumentable::Function,
                             args,
                             &scope.values,
+                            bindings,
                             &checker.settings.dummy_variable_rgx,
                         )
                     } else {
@@ -117,6 +128,7 @@ pub fn unused_arguments(checker: &Checker, parent: &Scope, scope: &Scope) -> Vec
                             &Argumentable::Method,
                             args,
                             &scope.values,
+                            bindings,
                             &checker.settings.dummy_variable_rgx,
                         )
                     } else {
@@ -136,6 +148,7 @@ pub fn unused_arguments(checker: &Checker, parent: &Scope, scope: &Scope) -> Vec
                             &Argumentable::ClassMethod,
                             args,
                             &scope.values,
+                            bindings,
                             &checker.settings.dummy_variable_rgx,
                         )
                     } else {
@@ -155,6 +168,7 @@ pub fn unused_arguments(checker: &Checker, parent: &Scope, scope: &Scope) -> Vec
                             &Argumentable::StaticMethod,
                             args,
                             &scope.values,
+                            bindings,
                             &checker.settings.dummy_variable_rgx,
                         )
                     } else {
@@ -173,6 +187,7 @@ pub fn unused_arguments(checker: &Checker, parent: &Scope, scope: &Scope) -> Vec
                     &Argumentable::Lambda,
                     args,
                     &scope.values,
+                    bindings,
                     &checker.settings.dummy_variable_rgx,
                 )
             } else {

src/fs.rs

@@ -5,15 +5,13 @@ use std::path::{Path, PathBuf};
 
 use anyhow::{anyhow, Result};
 use globset::GlobMatcher;
-use log::debug;
 use path_absolutize::{path_dedot, Absolutize};
 use rustc_hash::FxHashSet;
-use walkdir::{DirEntry, WalkDir};
 
 use crate::checks::CheckCode;
 
 /// Extract the absolute path and basename (as strings) from a Path.
-fn extract_path_names(path: &Path) -> Result<(&str, &str)> {
+pub fn extract_path_names(path: &Path) -> Result<(&str, &str)> {
     let file_path = path
         .to_str()
         .ok_or_else(|| anyhow!("Unable to parse filename: {:?}", path))?;
@@ -25,62 +23,7 @@ fn extract_path_names(path: &Path) -> Result<(&str, &str)> {
     Ok((file_path, file_basename))
 }
 
-fn is_excluded(file_path: &str, file_basename: &str, exclude: &globset::GlobSet) -> bool {
-    exclude.is_match(file_path) || exclude.is_match(file_basename)
-}
-
-fn is_included(path: &Path) -> bool {
-    let file_name = path.to_string_lossy();
-    file_name.ends_with(".py") || file_name.ends_with(".pyi")
-}
-
-pub fn iter_python_files<'a>(
-    path: &'a Path,
-    exclude: &'a globset::GlobSet,
-    extend_exclude: &'a globset::GlobSet,
-) -> impl Iterator<Item = Result<DirEntry, walkdir::Error>> + 'a {
-    // Run some checks over the provided patterns, to enable optimizations below.
-    let has_exclude = !exclude.is_empty();
-    let has_extend_exclude = !extend_exclude.is_empty();
-
-    WalkDir::new(normalize_path(path))
-        .into_iter()
-        .filter_entry(move |entry| {
-            if !has_exclude && !has_extend_exclude {
-                return true;
-            }
-
-            let path = entry.path();
-            match extract_path_names(path) {
-                Ok((file_path, file_basename)) => {
-                    if has_exclude && is_excluded(file_path, file_basename, exclude) {
-                        debug!("Ignored path via `exclude`: {:?}", path);
-                        false
-                    } else if has_extend_exclude
-                        && is_excluded(file_path, file_basename, extend_exclude)
-                    {
-                        debug!("Ignored path via `extend-exclude`: {:?}", path);
-                        false
-                    } else {
-                        true
-                    }
-                }
-                Err(e) => {
-                    debug!("Ignored path due to error in parsing: {:?}: {}", path, e);
-                    true
-                }
-            }
-        })
-        .filter(|entry| {
-            entry.as_ref().map_or(true, |entry| {
-                (entry.depth() == 0 || is_included(entry.path()))
-                    && !entry.file_type().is_dir()
-                    && !(entry.file_type().is_symlink() && entry.path().is_dir())
-            })
-        })
-}
-
-/// Create tree set with codes matching the pattern/code pairs.
+/// Create a set with codes matching the pattern/code pairs.
 pub(crate) fn ignores_from_path<'a>(
     path: &Path,
     pattern_code_pairs: &'a [(GlobMatcher, GlobMatcher, FxHashSet<CheckCode>)],
@@ -128,114 +71,3 @@ pub(crate) fn read_file(path: &Path) -> Result<String> {
     buf_reader.read_to_string(&mut contents)?;
     Ok(contents)
 }
-
-#[cfg(test)]
-mod tests {
-    use std::path::{Path, PathBuf};
-
-    use anyhow::Result;
-    use globset::GlobSet;
-    use path_absolutize::Absolutize;
-
-    use crate::fs::{extract_path_names, is_excluded, is_included};
-    use crate::settings::types::FilePattern;
-
-    #[test]
-    fn inclusions() {
-        let path = Path::new("foo/bar/baz.py").absolutize().unwrap();
-        assert!(is_included(&path));
-
-        let path = Path::new("foo/bar/baz.pyi").absolutize().unwrap();
-        assert!(is_included(&path));
-
-        let path = Path::new("foo/bar/baz.js").absolutize().unwrap();
-        assert!(!is_included(&path));
-
-        let path = Path::new("foo/bar/baz").absolutize().unwrap();
-        assert!(!is_included(&path));
-    }
-
-    fn make_exclusion(file_pattern: FilePattern, project_root: Option<&PathBuf>) -> GlobSet {
-        let mut builder = globset::GlobSetBuilder::new();
-        file_pattern.add_to(&mut builder, project_root).unwrap();
-        builder.build().unwrap()
-    }
-
-    #[test]
-    fn exclusions() -> Result<()> {
-        let project_root = Path::new("/tmp/");
-
-        let path = Path::new("foo").absolutize_from(project_root).unwrap();
-        let exclude = FilePattern::User("foo".to_string());
-        let (file_path, file_basename) = extract_path_names(&path)?;
-        assert!(is_excluded(
-            file_path,
-            file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
-        ));
-
-        let path = Path::new("foo/bar").absolutize_from(project_root).unwrap();
-        let exclude = FilePattern::User("bar".to_string());
-        let (file_path, file_basename) = extract_path_names(&path)?;
-        assert!(is_excluded(
-            file_path,
-            file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
-        ));
-
-        let path = Path::new("foo/bar/baz.py")
-            .absolutize_from(project_root)
-            .unwrap();
-        let exclude = FilePattern::User("baz.py".to_string());
-        let (file_path, file_basename) = extract_path_names(&path)?;
-        assert!(is_excluded(
-            file_path,
-            file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
-        ));
-
-        let path = Path::new("foo/bar").absolutize_from(project_root).unwrap();
-        let exclude = FilePattern::User("foo/bar".to_string());
-        let (file_path, file_basename) = extract_path_names(&path)?;
-        assert!(is_excluded(
-            file_path,
-            file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
-        ));
-
-        let path = Path::new("foo/bar/baz.py")
-            .absolutize_from(project_root)
-            .unwrap();
-        let exclude = FilePattern::User("foo/bar/baz.py".to_string());
-        let (file_path, file_basename) = extract_path_names(&path)?;
-        assert!(is_excluded(
-            file_path,
-            file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
-        ));
-
-        let path = Path::new("foo/bar/baz.py")
-            .absolutize_from(project_root)
-            .unwrap();
-        let exclude = FilePattern::User("foo/bar/*.py".to_string());
-        let (file_path, file_basename) = extract_path_names(&path)?;
-        assert!(is_excluded(
-            file_path,
-            file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
-        ));
-
-        let path = Path::new("foo/bar/baz.py")
-            .absolutize_from(project_root)
-            .unwrap();
-        let exclude = FilePattern::User("baz".to_string());
-        let (file_path, file_basename) = extract_path_names(&path)?;
-        assert!(!is_excluded(
-            file_path,
-            file_basename,
-            &make_exclusion(exclude, Some(&project_root.to_path_buf()))
-        ));
-
-        Ok(())
-    }
-}

src/isort/helpers.rs

@@ -0,0 +1,55 @@
+use rustpython_ast::Stmt;
+
+use crate::source_code_locator::SourceCodeLocator;
+
+/// Return `true` if a `Stmt` is preceded by a "comment break"
+pub fn has_comment_break(stmt: &Stmt, locator: &SourceCodeLocator) -> bool {
+    // Starting from the `Stmt` (`def f(): pass`), we want to detect patterns like
+    // this:
+    //
+    //   import os
+    //
+    //   # Detached comment.
+    //
+    //   def f(): pass
+
+    // This should also be detected:
+    //
+    //   import os
+    //
+    //   # Detached comment.
+    //
+    //   # Direct comment.
+    //   def f(): pass
+
+    // But this should not:
+    //
+    //   import os
+    //
+    //   # Direct comment.
+    //   def f(): pass
+    let mut seen_blank = false;
+    for line in locator
+        .slice_source_code_until(&stmt.location)
+        .lines()
+        .rev()
+    {
+        let line = line.trim();
+        if seen_blank {
+            if line.starts_with('#') {
+                return true;
+            } else if !line.is_empty() {
+                break;
+            }
+        } else {
+            if line.is_empty() {
+                seen_blank = true;
+            } else if line.starts_with('#') || line.starts_with('@') {
+                continue;
+            } else {
+                break;
+            }
+        }
+    }
+    false
+}

src/isort/mod.rs

@@ -18,6 +18,7 @@ use crate::isort::types::{
 mod categorize;
 mod comments;
 pub mod format;
+mod helpers;
 pub mod plugins;
 pub mod settings;
 mod sorting;
@@ -559,6 +560,7 @@ mod tests {
     #[test_case(Path::new("force_wrap_aliases.py"))]
     #[test_case(Path::new("import_from_after_import.py"))]
     #[test_case(Path::new("insert_empty_lines.py"))]
+    #[test_case(Path::new("insert_empty_lines.pyi"))]
     #[test_case(Path::new("leading_prefix.py"))]
     #[test_case(Path::new("no_reorder_within_section.py"))]
     #[test_case(Path::new("no_wrap_star.py"))]

src/isort/plugins.rs

@@ -19,14 +19,12 @@ fn extract_range(body: &[&Stmt]) -> Range {
     }
 }
 
-fn extract_indentation(body: &[&Stmt], locator: &SourceCodeLocator) -> String {
+fn extract_indentation_range(body: &[&Stmt]) -> Range {
     let location = body.first().unwrap().location;
-    let range = Range {
+    Range {
         location: Location::new(location.row(), 0),
         end_location: location,
-    };
-    let existing = locator.slice_source_code_range(&range);
-    leading_space(&existing)
+    }
 }
 
 /// I001
@@ -36,8 +34,10 @@ pub fn check_imports(
     settings: &Settings,
     autofix: bool,
 ) -> Option<Check> {
+    let indentation = locator.slice_source_code_range(&extract_indentation_range(&block.imports));
+    let indentation = leading_space(&indentation);
+
     let range = extract_range(&block.imports);
-    let indentation = extract_indentation(&block.imports, locator);
 
     // Extract comments. Take care to grab any inline comments from the last line.
     let comments = comments::collect_comments(
@@ -77,7 +77,7 @@ pub fn check_imports(
             if has_leading_content {
                 content.push('\n');
             }
-            content.push_str(&indent(&expected, &indentation));
+            content.push_str(&indent(&expected, indentation));
             check.amend(Fix::replacement(
                 content,
                 // Preserve leading prefix (but put the imports on a new line).
@@ -104,7 +104,7 @@ pub fn check_imports(
             let mut check = Check::new(CheckKind::UnsortedImports, range);
             if autofix && settings.fixable.contains(check.kind.code()) {
                 check.amend(Fix::replacement(
-                    indent(&expected, &indentation),
+                    indent(&expected, indentation),
                     range.location,
                     range.end_location,
                 ));

src/isort/settings.rs

@@ -32,11 +32,16 @@ pub struct Options {
                 test_id as test_id
             )
             ```
+
+            Note that this setting is only effective when combined with `combine-as-imports = true`.
+            When `combine-as-imports` isn't enabled, every aliased `import from` will be given its
+            own line, in which case, wrapping is not necessary.
         "#,
         default = r#"false"#,
         value_type = "bool",
         example = r#"
             force-wrap-aliases = true
+            combine-as-imports = true
         "#
     )]
     pub force_wrap_aliases: Option<bool>,

src/isort/snapshots/ruff__isort__tests__insert_empty_lines.py.snap

@@ -49,32 +49,17 @@ expression: checks
       column: 0
 - kind: UnsortedImports
   location:
-    row: 33
+    row: 52
     column: 0
   end_location:
-    row: 35
+    row: 54
     column: 0
   fix:
-    content: "    import collections\n    import typing\n\n"
+    content: "import os\n\n\n"
     location:
-      row: 33
+      row: 52
       column: 0
     end_location:
-      row: 35
-      column: 0
-- kind: UnsortedImports
-  location:
-    row: 39
-    column: 0
-  end_location:
-    row: 41
-    column: 0
-  fix:
-    content: "    import collections\n    import typing\n\n"
-    location:
-      row: 39
-      column: 0
-    end_location:
-      row: 41
+      row: 54
       column: 0
 

src/isort/snapshots/ruff__isort__tests__insert_empty_lines.pyi.snap

@@ -0,0 +1,50 @@
+---
+source: src/isort/mod.rs
+expression: checks
+---
+- kind: UnsortedImports
+  location:
+    row: 1
+    column: 0
+  end_location:
+    row: 3
+    column: 0
+  fix:
+    content: "import a\nimport b\n\n"
+    location:
+      row: 1
+      column: 0
+    end_location:
+      row: 3
+      column: 0
+- kind: UnsortedImports
+  location:
+    row: 4
+    column: 0
+  end_location:
+    row: 6
+    column: 0
+  fix:
+    content: "import os\nimport sys\n\n"
+    location:
+      row: 4
+      column: 0
+    end_location:
+      row: 6
+      column: 0
+- kind: UnsortedImports
+  location:
+    row: 14
+    column: 0
+  end_location:
+    row: 16
+    column: 0
+  fix:
+    content: "import os\nimport sys\n\n"
+    location:
+      row: 14
+      column: 0
+    end_location:
+      row: 16
+      column: 0
+

src/isort/snapshots/ruff__isort__tests__trailing_suffix.py.snap

@@ -25,7 +25,7 @@ expression: checks
     row: 6
     column: 13
   fix:
-    content: "    import os\n    import sys\n\n"
+    content: "    import os\n    import sys\n"
     location:
       row: 5
       column: 0

src/isort/track.rs

@@ -1,3 +1,5 @@
+use std::path::Path;
+
 use rustpython_ast::{
     Alias, Arg, Arguments, Boolop, Cmpop, Comprehension, Constant, Excepthandler,
     ExcepthandlerKind, Expr, ExprContext, Keyword, MatchCase, Operator, Pattern, Stmt, StmtKind,
@@ -6,30 +8,41 @@ use rustpython_ast::{
 
 use crate::ast::visitor::Visitor;
 use crate::directives::IsortDirectives;
+use crate::isort::helpers;
+use crate::source_code_locator::SourceCodeLocator;
 
+#[derive(Debug)]
 pub enum Trailer {
     Sibling,
     ClassDef,
     FunctionDef,
 }
 
-#[derive(Default)]
+#[derive(Debug, Default)]
 pub struct Block<'a> {
     pub imports: Vec<&'a Stmt>,
     pub trailer: Option<Trailer>,
 }
 
 pub struct ImportTracker<'a> {
-    blocks: Vec<Block<'a>>,
+    locator: &'a SourceCodeLocator<'a>,
     directives: &'a IsortDirectives,
+    pyi: bool,
+    blocks: Vec<Block<'a>>,
     split_index: usize,
     nested: bool,
 }
 
 impl<'a> ImportTracker<'a> {
-    pub fn new(directives: &'a IsortDirectives) -> Self {
+    pub fn new(
+        locator: &'a SourceCodeLocator<'a>,
+        directives: &'a IsortDirectives,
+        path: &'a Path,
+    ) -> Self {
         Self {
+            locator,
             directives,
+            pyi: path.extension().map_or(false, |ext| ext == "pyi"),
             blocks: vec![Block::default()],
             split_index: 0,
             nested: false,
@@ -41,6 +54,49 @@ impl<'a> ImportTracker<'a> {
         self.blocks[index].imports.push(stmt);
     }
 
+    fn trailer_for(&self, stmt: &'a Stmt) -> Option<Trailer> {
+        // No need to compute trailers if we won't be finalizing anything.
+        let index = self.blocks.len() - 1;
+        if self.blocks[index].imports.is_empty() {
+            return None;
+        }
+
+        // Similar to isort, avoid enforcing any newline behaviors in nested blocks.
+        if self.nested {
+            return None;
+        }
+
+        Some(if self.pyi {
+            // Black treats interface files differently, limiting to one newline
+            // (`Trailing::Sibling`).
+            Trailer::Sibling
+        } else {
+            // If the import block is followed by a class or function, we want to enforce
+            // two blank lines. The exception: if, between the import and the class or
+            // function, we have at least one commented line, followed by at
+            // least one blank line. In that case, we treat it as a regular
+            // sibling (i.e., as if the comment is the next statement, as
+            // opposed to the class or function).
+            match &stmt.node {
+                StmtKind::FunctionDef { .. } | StmtKind::AsyncFunctionDef { .. } => {
+                    if helpers::has_comment_break(stmt, self.locator) {
+                        Trailer::Sibling
+                    } else {
+                        Trailer::FunctionDef
+                    }
+                }
+                StmtKind::ClassDef { .. } => {
+                    if helpers::has_comment_break(stmt, self.locator) {
+                        Trailer::Sibling
+                    } else {
+                        Trailer::ClassDef
+                    }
+                }
+                _ => Trailer::Sibling,
+            }
+        })
+    }
+
     fn finalize(&mut self, trailer: Option<Trailer>) {
         let index = self.blocks.len() - 1;
         if !self.blocks[index].imports.is_empty() {
@@ -62,17 +118,7 @@ where
         // Track manual splits.
         while self.split_index < self.directives.splits.len() {
             if stmt.location.row() >= self.directives.splits[self.split_index] {
-                self.finalize(Some(if self.nested {
-                    Trailer::Sibling
-                } else {
-                    match &stmt.node {
-                        StmtKind::FunctionDef { .. } | StmtKind::AsyncFunctionDef { .. } => {
-                            Trailer::FunctionDef
-                        }
-                        StmtKind::ClassDef { .. } => Trailer::ClassDef,
-                        _ => Trailer::Sibling,
-                    }
-                }));
+                self.finalize(self.trailer_for(stmt));
                 self.split_index += 1;
             } else {
                 break;
@@ -87,17 +133,7 @@ where
         {
             self.track_import(stmt);
         } else {
-            self.finalize(Some(if self.nested {
-                Trailer::Sibling
-            } else {
-                match &stmt.node {
-                    StmtKind::FunctionDef { .. } | StmtKind::AsyncFunctionDef { .. } => {
-                        Trailer::FunctionDef
-                    }
-                    StmtKind::ClassDef { .. } => Trailer::ClassDef,
-                    _ => Trailer::Sibling,
-                }
-            }));
+            self.finalize(self.trailer_for(stmt));
         }
 
         // Track scope.

src/iterators.rs

@@ -0,0 +1,16 @@
+#[cfg(not(target_family = "wasm"))]
+use rayon::prelude::*;
+
+/// Shim that calls `par_iter` except for wasm because there's no wasm support
+/// in rayon yet (there is a shim to be used for the web, but it requires js
+/// cooperation) Unfortunately, `ParallelIterator` does not implement `Iterator`
+/// so the signatures diverge
+#[cfg(not(target_family = "wasm"))]
+pub fn par_iter<T: Sync>(iterable: &[T]) -> impl ParallelIterator<Item = &T> {
+    iterable.par_iter()
+}
+
+#[cfg(target_family = "wasm")]
+pub fn par_iter<T: Sync>(iterable: &[T]) -> impl Iterator<Item = &T> {
+    iterable.iter()
+}

src/lib.rs

@@ -14,13 +14,14 @@
 use std::path::Path;
 
 use anyhow::Result;
-use log::debug;
+use path_absolutize::path_dedot;
 use rustpython_helpers::tokenize;
 use rustpython_parser::lexer::LexResult;
 use settings::{pyproject, Settings};
 
 use crate::checks::Check;
 use crate::linter::check_path;
+use crate::resolver::Relativity;
 use crate::settings::configuration::Configuration;
 use crate::source_code_locator::SourceCodeLocator;
 
@@ -53,10 +54,12 @@ mod flake8_import_conventions;
 mod flake8_print;
 pub mod flake8_quotes;
 mod flake8_return;
+mod flake8_simplify;
 pub mod flake8_tidy_imports;
 mod flake8_unused_arguments;
 pub mod fs;
 mod isort;
+pub mod iterators;
 mod lex;
 pub mod linter;
 pub mod logging;
@@ -72,6 +75,7 @@ mod pygrep_hooks;
 mod pylint;
 mod python;
 mod pyupgrade;
+pub mod resolver;
 mod ruff;
 mod rustpython_helpers;
 pub mod settings;
@@ -81,24 +85,24 @@ pub mod updates;
 mod vendored;
 pub mod visibility;
 
+/// Load the relevant `Settings` for a given `Path`.
+fn resolve(path: &Path) -> Result<Settings> {
+    if let Some(pyproject) = pyproject::find_pyproject_toml(path) {
+        // First priority: `pyproject.toml` in the current `Path`.
+        resolver::resolve_settings(&pyproject, &Relativity::Parent, None)
+    } else if let Some(pyproject) = pyproject::find_user_pyproject_toml() {
+        // Second priority: user-specific `pyproject.toml`.
+        resolver::resolve_settings(&pyproject, &Relativity::Cwd, None)
+    } else {
+        // Fallback: default settings.
+        Settings::from_configuration(Configuration::default(), &path_dedot::CWD)
+    }
+}
+
 /// Run Ruff over Python source code directly.
 pub fn check(path: &Path, contents: &str, autofix: bool) -> Result<Vec<Check>> {
-    // Find the project root and pyproject.toml.
-    let project_root = pyproject::find_project_root(&[path.to_path_buf()]);
-    match &project_root {
-        Some(path) => debug!("Found project root at: {:?}", path),
-        None => debug!("Unable to identify project root; assuming current directory..."),
-    };
-    let pyproject = pyproject::find_pyproject_toml(project_root.as_ref());
-    match &pyproject {
-        Some(path) => debug!("Found pyproject.toml at: {:?}", path),
-        None => debug!("Unable to find pyproject.toml; using default settings..."),
-    };
-
-    let settings = Settings::from_configuration(
-        Configuration::from_pyproject(pyproject.as_ref(), project_root.as_ref())?,
-        project_root.as_ref(),
-    )?;
+    // Load the relevant `Settings` for the given `Path`.
+    let settings = resolve(path)?;
 
     // Tokenize once.
     let tokens: Vec<LexResult> = tokenize(contents);

src/linter.rs

@@ -92,6 +92,7 @@ pub(crate) fn check_path(
                         &directives.isort,
                         settings,
                         autofix,
+                        path,
                     ));
                 }
             }
@@ -210,7 +211,7 @@ pub fn add_noqa_to_path(path: &Path, settings: &Settings) -> Result<usize> {
 }
 
 /// Apply autoformatting to the source code at the given `Path`.
-pub fn autoformat_path(path: &Path) -> Result<()> {
+pub fn autoformat_path(path: &Path, _settings: &Settings) -> Result<()> {
     // Read the file from disk.
     let contents = fs::read_file(path)?;